Fix realloc(p, 0) to act like free(p).
Fix realloc(p, 0) to act like free(p).

Reported by Yoni Londer.

yy-nm/jemalloc,CMRemix/android_external_jemalloc,flyfeifan/jemalloc,ahmetmircik/jemalloc,geekboxzone/lollipop_external_jemalloc,android-ia/platform_external_jemalloc,xin3liang/platform_external_jemalloc,Dmitry-Me/jemalloc,glandium/jemalloc,sudosurootdev/external_jemalloc,8l/jemalloc,kmiku7/jemalloc,AndroidExternal/jemalloc,geekboxzone/mmallow_external_jemalloc,cpeterso/jemalloc,lilothar/jemalloc,xin3liang/platform_external_jemalloc,awreece/jemalloc,Dmitry-Me/jemalloc,garoose/jemalloc,kmiku7/jemalloc,CMRemix/android_external_jemalloc,8l/jemalloc,8l/jemalloc,jemalloc/jemalloc-cmake,jemalloc/jemalloc-cmake,AndroidExternal/jemalloc,wespelee/jemalloc,lilothar/jemalloc,percona/jemalloc-debian,geekboxzone/lollipop_external_jemalloc,android-ia/platform_external_jemalloc,dxq-git/jemalloc,shekkbuilder/jemalloc,shekkbuilder/jemalloc,percona/jemalloc-debian,CyanogenMod/android_external_jemalloc,lvfeng1130/jemalloc,garoose/jemalloc,glandium/jemalloc,lilothar/jemalloc,splbio/jemalloc,vashstorm/jemalloc,VRToxin/android_external_jemalloc,TeamExodus/external_jemalloc,wqfish/jemalloc,geekboxzone/mmallow_external_jemalloc,dxq-git/jemalloc,vashstorm/jemalloc,ahmetmircik/jemalloc,splbio/jemalloc,awreece/jemalloc,vashstorm/jemalloc,wfxiang08/jemalloc,shekkbuilder/jemalloc,kmiku7/jemalloc,VRToxin/android_external_jemalloc,percona/jemalloc-debian,ahmetmircik/jemalloc,leebaok/jemalloc-4.2.1-readcode,leebaok/jemalloc-4.2.1-readcode,glandium/jemalloc,splbio/jemalloc,dxq-git/jemalloc,leebaok/jemalloc-4.2.1-readcode,wqfish/jemalloc,lilothar/jemalloc,TeamExodus/external_jemalloc,AndroidExternal/jemalloc,leebaok/jemalloc-4.2.1-readcode,garoose/jemalloc,Snaipe/jemalloc,yy-nm/jemalloc,VRToxin/android_external_jemalloc,CMRemix/android_external_jemalloc,flyfeifan/jemalloc,android-ia/platform_external_jemalloc,flyfeifan/jemalloc,glandium/jemalloc,yy-nm/jemalloc,8l/jemalloc,wespelee/jemalloc,CMRemix/android_external_jemalloc,CyanogenMod/android_external_jemalloc,vashstorm/jemalloc,cpeterso/jemalloc,Snaipe/jemalloc,Dmitry-Me/jemalloc,wfxiang08/jemalloc,android-ia/platform_external_jemalloc,lvfeng1130/jemalloc,xin3liang/platform_external_jemalloc,tempbottle/jemalloc,wfxiang08/jemalloc,tempbottle/jemalloc,tempbottle/jemalloc,wespelee/jemalloc,Dmitry-Me/jemalloc,yy-nm/jemalloc,CyanogenMod/android_external_jemalloc,geekboxzone/mmallow_external_jemalloc,lvfeng1130/jemalloc,wespelee/jemalloc,geekboxzone/lollipop_external_jemalloc,awreece/jemalloc,wqfish/jemalloc,xin3liang/platform_external_jemalloc,wfxiang08/jemalloc,VRToxin/android_external_jemalloc,geekboxzone/lollipop_external_jemalloc,TeamExodus/external_jemalloc,kmiku7/jemalloc,Snaipe/jemalloc,dxq-git/jemalloc,Snaipe/jemalloc,percona/jemalloc-debian,lvfeng1130/jemalloc,awreece/jemalloc,tempbottle/jemalloc,sudosurootdev/external_jemalloc,TeamExodus/external_jemalloc,cpeterso/jemalloc,AndroidExternal/jemalloc,sudosurootdev/external_jemalloc,CyanogenMod/android_external_jemalloc,jemalloc/jemalloc-cmake,flyfeifan/jemalloc,garoose/jemalloc,cpeterso/jemalloc,sudosurootdev/external_jemalloc,wqfish/jemalloc,wqfish/jemalloc,jemalloc/jemalloc-cmake,geekboxzone/mmallow_external_jemalloc,shekkbuilder/jemalloc,ahmetmircik/jemalloc