Tweak x86 -mcpu defaults.
 - Default to yonah on Darwin (to get SSE3).

 - Default to Pentium4 (32-bit) and x86-64 (64-bit) on
   non-Darwin. Welcome to the 21st century.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@71069 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed