Specifying minimum java memory -Xms when we run buck_tool.py
Specifying minimum java memory -Xms when we run buck_tool.py

Summary:
Java by default will pick the following values for the -Xms parameter which seems to be insufficient in some cases. Explicitly setting this to 64mb every time we run it inside buck_tool.py.

 -server mode: 25% of the amount of free physical memory in the system, up to 64 MB and at least 8 MB
 -client mode: 25% of the amount of free physical memory in the system, up to 16 MB and at least 8 MB

https://docs.oracle.com/cd/E13150_01/jrockit_jvm/jrockit/jrdocs/refman/optionX.html

Test Plan: buck test

illicitonion/buck,raviagarwal7/buck,vine/buck,zhan-xiong/buck,daedric/buck,LegNeato/buck,rmaz/buck,robbertvanginkel/buck,daedric/buck,darkforestzero/buck,darkforestzero/buck,illicitonion/buck,JoelMarcey/buck,shs96c/buck,raviagarwal7/buck,ilya-klyuchnikov/buck,mikekap/buck,brettwooldridge/buck,brettwooldridge/buck,shybovycha/buck,janicduplessis/buck,rmaz/buck,kageiit/buck,OkBuilds/buck,daedric/buck,rowillia/buck,Addepar/buck,vine/buck,mogers/buck,zhan-xiong/buck,nguyentruongtho/buck,mogers/buck,shybovycha/buck,mogers/buck,illicitonion/buck,clonetwin26/buck,janicduplessis/buck,illicitonion/buck,justinmuller/buck,vine/buck,illicitonion/buck,k21/buck,OkBuilds/buck,daedric/buck,robbertvanginkel/buck,marcinkwiatkowski/buck,LegNeato/buck,ilya-klyuchnikov/buck,romanoid/buck,nguyentruongtho/buck,Addepar/buck,rhencke/buck,illicitonion/buck,Addepar/buck,vine/buck,vine/buck,k21/buck,clonetwin26/buck,robbertvanginkel/buck,daedric/buck,mikekap/buck,rhencke/buck,kageiit/buck,illicitonion/buck,grumpyjames/buck,mogers/buck,janicduplessis/buck,illicitonion/buck,LegNeato/buck,marcinkwiatkowski/buck,marcinkwiatkowski/buck,JoelMarcey/buck,mikekap/buck,liuyang-li/buck,janicduplessis/buck,janicduplessis/buck,bocon13/buck,SeleniumHQ/buck,bocon13/buck,sdwilsh/buck,SeleniumHQ/buck,mikekap/buck,vschs007/buck,liuyang-li/buck,kageiit/buck,marcinkwiatkowski/buck,zhan-xiong/buck,OkBuilds/buck,k21/buck,daedric/buck,OkBuilds/buck,daedric/buck,mikekap/buck,facebook/buck,Dominator008/buck,vschs007/buck,nguyentruongtho/buck,facebook/buck,justinmuller/buck,Dominator008/buck,justinmuller/buck,nguyentruongtho/buck,darkforestzero/buck,grumpyjames/buck,justinmuller/buck,k21/buck,vschs007/buck,clonetwin26/buck,bocon13/buck,LegNeato/buck,JoelMarcey/buck,davido/buck,dsyang/buck,shs96c/buck,OkBuilds/buck,JoelMarcey/buck,ilya-klyuchnikov/buck,rowillia/buck,justinmuller/buck,darkforestzero/buck,Distrotech/buck,sdwilsh/buck,brettwooldridge/buck,grumpyjames/buck,OkBuilds/buck,SeleniumHQ/buck,mikekap/buck,brettwooldridge/buck,bocon13/buck,justinmuller/buck,zpao/buck,rmaz/buck,zpao/buck,zpao/buck,rowillia/buck,daedric/buck,ilya-klyuchnikov/buck,rmaz/buck,grumpyjames/buck,zpao/buck,rowillia/buck,ilya-klyuchnikov/buck,janicduplessis/buck,liuyang-li/buck,vschs007/buck,robbertvanginkel/buck,kageiit/buck,vschs007/buck,Addepar/buck,rowillia/buck,bocon13/buck,darkforestzero/buck,k21/buck,rhencke/buck,raviagarwal7/buck,k21/buck,mogers/buck,darkforestzero/buck,grumpyjames/buck,dsyang/buck,grumpyjames/buck,sdwilsh/buck,rowillia/buck,facebook/buck,romanoid/buck,raviagarwal7/buck,marcinkwiatkowski/buck,brettwooldridge/buck,justinmuller/buck,zhan-xiong/buck,k21/buck,rhencke/buck,clonetwin26/buck,vine/buck,SeleniumHQ/buck,vschs007/buck,Distrotech/buck,raviagarwal7/buck,vine/buck,davido/buck,grumpyjames/buck,JoelMarcey/buck,ilya-klyuchnikov/buck,Dominator008/buck,illicitonion/buck,dsyang/buck,rmaz/buck,vschs007/buck,darkforestzero/buck,shybovycha/buck,Distrotech/buck,k21/buck,rmaz/buck,shs96c/buck,brettwooldridge/buck,JoelMarcey/buck,Addepar/buck,raviagarwal7/buck,bocon13/buck,rowillia/buck,nguyentruongtho/buck,liuyang-li/buck,mogers/buck,rhencke/buck,romanoid/buck,rhencke/buck,darkforestzero/buck,ilya-klyuchnikov/buck,dsyang/buck,zhan-xiong/buck,zhan-xiong/buck,rowillia/buck,vschs007/buck,shybovycha/buck,marcinkwiatkowski/buck,raviagarwal7/buck,janicduplessis/buck,janicduplessis/buck,rhencke/buck,sdwilsh/buck,JoelMarcey/buck,k21/buck,SeleniumHQ/buck,JoelMarcey/buck,kageiit/buck,daedric/buck,SeleniumHQ/buck,brettwooldridge/buck,zpao/buck,justinmuller/buck,k21/buck,clonetwin26/buck,facebook/buck,LegNeato/buck,robbertvanginkel/buck,daedric/buck,vine/buck,darkforestzero/buck,illicitonion/buck,shybovycha/buck,shs96c/buck,kageiit/buck,zhan-xiong/buck,facebook/buck,nguyentruongtho/buck,shs96c/buck,davido/buck,shybovycha/buck,romanoid/buck,Distrotech/buck,davido/buck,marcinkwiatkowski/buck,LegNeato/buck,SeleniumHQ/buck,shybovycha/buck,ilya-klyuchnikov/buck,romanoid/buck,brettwooldridge/buck,sdwilsh/buck,romanoid/buck,shybovycha/buck,dsyang/buck,shybovycha/buck,grumpyjames/buck,Dominator008/buck,vschs007/buck,davido/buck,k21/buck,romanoid/buck,LegNeato/buck,nguyentruongtho/buck,shs96c/buck,dsyang/buck,clonetwin26/buck,clonetwin26/buck,daedric/buck,ilya-klyuchnikov/buck,janicduplessis/buck,kageiit/buck,marcinkwiatkowski/buck,janicduplessis/buck,JoelMarcey/buck,davido/buck,vschs007/buck,rhencke/buck,OkBuilds/buck,dsyang/buck,ilya-klyuchnikov/buck,daedric/buck,mogers/buck,LegNeato/buck,shs96c/buck,shs96c/buck,Distrotech/buck,SeleniumHQ/buck,davido/buck,robbertvanginkel/buck,liuyang-li/buck,Dominator008/buck,ilya-klyuchnikov/buck,Distrotech/buck,marcinkwiatkowski/buck,Dominator008/buck,mikekap/buck,Dominator008/buck,liuyang-li/buck,zpao/buck,Addepar/buck,bocon13/buck,dsyang/buck,facebook/buck,rhencke/buck,zhan-xiong/buck,OkBuilds/buck,clonetwin26/buck,brettwooldridge/buck,Dominator008/buck,romanoid/buck,Distrotech/buck,romanoid/buck,mogers/buck,Dominator008/buck,JoelMarcey/buck,marcinkwiatkowski/buck,OkBuilds/buck,davido/buck,k21/buck,shs96c/buck,marcinkwiatkowski/buck,darkforestzero/buck,clonetwin26/buck,justinmuller/buck,grumpyjames/buck,dsyang/buck,SeleniumHQ/buck,davido/buck,rowillia/buck,clonetwin26/buck,janicduplessis/buck,daedric/buck,bocon13/buck,vschs007/buck,rowillia/buck,liuyang-li/buck,Distrotech/buck,bocon13/buck,Addepar/buck,OkBuilds/buck,vine/buck,shs96c/buck,zhan-xiong/buck,rowillia/buck,davido/buck,OkBuilds/buck,shybovycha/buck,bocon13/buck,darkforestzero/buck,JoelMarcey/buck,davido/buck,romanoid/buck,illicitonion/buck,OkBuilds/buck,shybovycha/buck,dsyang/buck,mikekap/buck,LegNeato/buck,Dominator008/buck,clonetwin26/buck,shs96c/buck,vine/buck,darkforestzero/buck,bocon13/buck,zhan-xiong/buck,brettwooldridge/buck,raviagarwal7/buck,liuyang-li/buck,rmaz/buck,mikekap/buck,grumpyjames/buck,sdwilsh/buck,raviagarwal7/buck,dsyang/buck,dsyang/buck,davido/buck,Distrotech/buck,SeleniumHQ/buck,zhan-xiong/buck,Addepar/buck,bocon13/buck,justinmuller/buck,brettwooldridge/buck,robbertvanginkel/buck,darkforestzero/buck,zpao/buck,mikekap/buck,rmaz/buck,rmaz/buck,mogers/buck,mikekap/buck,rhencke/buck,mogers/buck,rmaz/buck,sdwilsh/buck,justinmuller/buck,shybovycha/buck,vschs007/buck,LegNeato/buck,clonetwin26/buck,facebook/buck,rmaz/buck,rhencke/buck,vschs007/buck,robbertvanginkel/buck,LegNeato/buck,mikekap/buck,JoelMarcey/buck,romanoid/buck,OkBuilds/buck,robbertvanginkel/buck,grumpyjames/buck,robbertvanginkel/buck,Addepar/buck,vine/buck,robbertvanginkel/buck,raviagarwal7/buck,justinmuller/buck,sdwilsh/buck,k21/buck,rmaz/buck,LegNeato/buck,liuyang-li/buck,Addepar/buck,illicitonion/buck,liuyang-li/buck,Addepar/buck,ilya-klyuchnikov/buck,raviagarwal7/buck,shybovycha/buck,mogers/buck,sdwilsh/buck,marcinkwiatkowski/buck,SeleniumHQ/buck,SeleniumHQ/buck,Distrotech/buck,ilya-klyuchnikov/buck,dsyang/buck,brettwooldridge/buck,liuyang-li/buck,robbertvanginkel/buck,justinmuller/buck,zhan-xiong/buck,Addepar/buck,illicitonion/buck,grumpyjames/buck,sdwilsh/buck,clonetwin26/buck,sdwilsh/buck,Addepar/buck,Dominator008/buck,sdwilsh/buck,raviagarwal7/buck,sdwilsh/buck,Dominator008/buck,zhan-xiong/buck,brettwooldridge/buck,shs96c/buck,shs96c/buck,marcinkwiatkowski/buck,romanoid/buck,JoelMarcey/buck,raviagarwal7/buck,davido/buck,rmaz/buck,robbertvanginkel/buck,rowillia/buck,romanoid/buck,Distrotech/buck,janicduplessis/buck,SeleniumHQ/buck,LegNeato/buck