FIX: memcpy_76(): add support for non-ARM architectures

Before, memcpy_76() assumed ARM instruction set.  Add preprocessor
guards to use generic memcpy() if not on ARM.

Original patch had args to memcpy_76 backwards.

Change-Id: Ib5375e9de28ab6c2b348731dcdf282d6f7a529c1
skia: SkPaint::SkPaint(): don't cast away const

This will help avoid bugs like the one fixed in change-id:
Iaeb2b84b6696e3eebf29617dfdc41c55e5226776.

Change-Id: I892423e18f9927f827393d0ff0c923259e07389c