Makefile.vc: add rudimentary Windows ARM support
Makefile.vc: add rudimentary Windows ARM support

untested

builds only libwebp (targeting windows phone), with threading disabled
for now due to the use of desktop specific threading API

Change-Id: Idf3057a73c88e1a672ffe0a7c72d2626d701b706

Aexyn/libwebp,matanbs/webm.libwebp,altogother/webm.libwebp,abwiz0086/webm.libwebp,webmproject/libwebp,kalli123/webm.libwebp,redengineer/libwebp,Aexyn/libwebp,gshORTON/webm.libwebp,kleopatra999/webm.libwebp,ericmckean/webm.libwebp,ya7lelkom/libwebp,imazen/libwebp,reimaginemedia/webm.libwebp,rxl194/libwebp,kalli123/webm.libwebp,kim42083/webm.libwebp,jiehu5114/libwebp,abwiz0086/webm.libwebp,altogother/webm.libwebp,iniwf/webm.libwebp,Acidburn0zzz/webm.libwebp,kleopatra999/webm.libwebp,kim42083/webm.libwebp,kleopatra999/webm.libwebp,Acidburn0zzz/webm.libwebp,ttyangf/libwebp,iniwf/webm.libwebp,jiehu5114/libwebp,ericmckean/webm.libwebp,zofuthan/libwebp,Maria1099/webm.libwebp,ttyangf/libwebp,Aexyn/libwebp,rxl194/libwebp,iniwf/webm.libwebp,yohunl/libwebp,jacklicn/libwebp,PKRoma/libwebp,ericmckean/webm.libwebp,redengineer/libwebp,kim42083/webm.libwebp,matanbs/webm.libwebp,altogother/webm.libwebp,ttyangf/libwebp,PKRoma/libwebp,jiehu5114/libwebp,reimaginemedia/webm.libwebp,rxl194/libwebp,imazen/libwebp,Acidburn0zzz/webm.libwebp,kalli123/webm.libwebp,Acidburn0zzz/webm.libwebp,matanbs/webm.libwebp,Maria1099/webm.libwebp,yohunl/libwebp,matanbs/webm.libwebp,ya7lelkom/libwebp,kalli123/webm.libwebp,altogother/webm.libwebp,ya7lelkom/libwebp,rxl194/libwebp,imazen/libwebp,webmproject/libwebp,iniwf/webm.libwebp,gshORTON/webm.libwebp,zofuthan/libwebp,ericmckean/webm.libwebp,jiehu5114/libwebp,reimaginemedia/webm.libwebp,yohunl/libwebp,abwiz0086/webm.libwebp,kim42083/webm.libwebp,kleopatra999/webm.libwebp,altogother/webm.libwebp,redengineer/libwebp,Aexyn/libwebp,redengineer/libwebp,PKRoma/libwebp,Suvarna1488/webm.libwebp,ya7lelkom/libwebp,reimaginemedia/webm.libwebp,jacklicn/libwebp,jacklicn/libwebp,imazen/libwebp,jiehu5114/libwebp,Suvarna1488/webm.libwebp,Acidburn0zzz/webm.libwebp,Aexyn/libwebp,Suvarna1488/webm.libwebp,abwiz0086/webm.libwebp,Maria1099/webm.libwebp,gshORTON/webm.libwebp,Suvarna1488/webm.libwebp,imazen/libwebp,zofuthan/libwebp,yohunl/libwebp,yohunl/libwebp,PKRoma/libwebp,kalli123/webm.libwebp,Suvarna1488/webm.libwebp,webmproject/libwebp,ya7lelkom/libwebp,PKRoma/libwebp,Maria1099/webm.libwebp,ttyangf/libwebp,redengineer/libwebp,ericmckean/webm.libwebp,zofuthan/libwebp,zofuthan/libwebp,matanbs/webm.libwebp,kleopatra999/webm.libwebp,ttyangf/libwebp,PKRoma/libwebp,abwiz0086/webm.libwebp,Maria1099/webm.libwebp,iniwf/webm.libwebp,webmproject/libwebp,jacklicn/libwebp,reimaginemedia/webm.libwebp,webmproject/libwebp,gshORTON/webm.libwebp,jacklicn/libwebp,rxl194/libwebp,gshORTON/webm.libwebp,kim42083/webm.libwebp