[PowerPC] This revision adds 68 of the missing "Predefined Functions for...

[PowerPC] This revision adds 68 of the missing "Predefined Functions for Vector Programming" from appendix A of the OpenPOWER ABI for Linux Supplement document.

I also added tests for the new functions and updated another test that was looking for specific line numbers in error messages from altivec.h.

https://llvm.org/bugs/show_bug.cgi?id=23679

http://reviews.llvm.org/D10131

llvm-svn: 239066