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

Change-Id: Id4d7335332f4086fa33641630f41810b2fe07031

aways-CR/android_external_skia,aways-CR/android_external_skia,aways-CR/android_external_skia,aways-CR/android_external_skia