[driver] Add a dump method for ArgList.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@175777 91177308-0d34-0410-b5e6-96231b3b80d8
Preprocessor: preserve whitespace in -traditional-cpp mode.

Note that unlike GNU cpp we currently do not preserve whitespace in macros
(even in -traditional-cpp mode).

<rdar://problem/12897179>

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@175778 91177308-0d34-0410-b5e6-96231b3b80d8
[driver] Handle the processing of the QA_OVERRIDE_GCC3_OPTIONS and CCC_ADD_ARGS
before the DiagnosticsEngine is instantiated.  Otherwise, warning options are
not handled correctly.
rdar://13254743

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@175779 91177308-0d34-0410-b5e6-96231b3b80d8