Driver: Add two special groups of "whitelisted" options which we know

Driver: Add two special groups of "whitelisted" options which we know
clang doesn't support, and don't want to warn are unused. Eventually
these should disappear.

Here is a more readable list than is in the diff:

W options: -Wall, -Wcast-align, -Wchar-align, -Wchar-subscripts,
-Werror, -Wextra, -Winline, -Wint-to-pointer-cast, -Wmissing-braces,
-Wmost, -Wnested-externs, -Wno-format-y2k, -Wno-four-char-constants,
-Wno-missing-field-initializers, -Wno-trigraphs, -Wno-unknown-pragmas,
-Wno-unused-parameter, -Wparentheses, -Wpointer-arith,
-Wpointer-to-int-cast, -Wreturn-type, -Wshorten-64-to-32, -Wswitch,
-Wunused-function, -Wunused-label, -Wunused-value, -Wunused-variable,
-Wwrite-strings.

f options: -fasm-blocks, -fmessage-length=.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@67549 91177308-0d34-0410-b5e6-96231b3b80d8