Revert "Use filename in linemarker when compiling preprocessed source"

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.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@293032 91177308-0d34-0410-b5e6-96231b3b80d8