Fix expected column numbers in two tests.

This is a minor fix to two tsan tests that were expecting the wrong
column information. Now that clang emits column information by default
in its debugging output, the tests had started failing.
[RuntimeDyld] Replace a crufty old ARM RuntimeDyld test with a new one that uses
RuntimeDyldChecker.

This allows us to remove one of the six remaining object files in the LLVM
source tree.
Enable -gcolumn-info by default.

This patch flips the default value for -gcolumn-info to be on by
default. I discussed the rationale and provided compile/size data
in:

http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-June/074290.html

This also updates the documentation and some tests that relied on
the lack of column information. Some tests had column information
in the expected output, but it was wrong (the tsan tests). Others
were using the driver to execute.