[PATCH] Let "-w" ignore all warnings

[Jordan Rose]

  IMHO this is the wrong thing to do. Warnings that are errors by default are errors for a good reason: it is usually //very// hard to find a legitimate use case. I see that -Wstatic-float-init is actually something reasonable to do, but the warning text just suggests adding `constexpr`; is that so hard to do? (Is that incompatible with other C++11 compilers?)

  Put this way: if -Wstatic-float-init were a hard error with a fixit, wouldn't you just accept the fixit and move on, even though Clang can perfectly well tell what you want to do?

http://llvm-reviews.chandlerc.com/D551