Revert "Use filename in linemarker when compiling preprocessed source"

This reverts commit r293004 because it broke the buildbots with "unknown CPU"
errors. I tried to fix it in r293026, but that broke on Green Dragon with this
kind of error:

error: expected string not found in input
// CHECK: l{{ +}}df{{ +}}*ABS*{{ +}}{{0+}}{{.+}}preprocessed-input.c{{$}}
          ^
<stdin>:2:1: note: scanning from here
/Users/buildslave/jenkins/sharedspace/incremental@2/clang-build/tools/clang/test/Frontend/Output/preprocessed-input.c.tmp.o: file format Mach-O 64-bit x86-64
^
<stdin>:2:67: note: possible intended match here
/Users/buildslave/jenkins/sharedspace/incremental@2/clang-build/tools/clang/test/Frontend/Output/preprocessed-input.c.tmp.o: file format Mach-O 64-bit x86-64

I suppose this means that llvm-objdump doesn't support Mach-O, so the test
should indeed check for linux (but not for x86). I'll leave it to someone that
knows better.

llvm-svn: 293032