PPCJITInfo.cpp: Tweak r186252 with s/__ppc/__powerpc/ to work on powerpc-linux Fedora 12.

    g++ (GCC) 4.4.4 20100630 (Red Hat 4.4.4-10)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186396 91177308-0d34-0410-b5e6-96231b3b80d8