first cut at making iOS work

Replace __arm__ with SK_CPU_ARM
add support for iOS simulator and device
fix const warning in iOSSampleApp
update gyp files

https://code.google.com/p/skia/issues/detail?id=900
tracks fixing missing arm assembly
Review URL: https://codereview.appspot.com/6552045

git-svn-id: http://skia.googlecode.com/svn/trunk/gyp@5606 2bbb7eff-a529-9590-31e7-b0007b416f81
5 files changed