* move fmaq from freestanding libc to compiler_rt, unconditionally
exported weak_odr.
* stage1: add fmaf, fmal, fmaq as symbols that compiler-rt might
generate calls to.
* stage1: lower `@mulAdd` directly to a call to `fmaq` instead of to
the LLVM intrinsic because LLVM will lower it to `fmal` even when the
target's `long double` is not equivalent to `f128`.
This commit is intended to fix the test suite which is failing on the
previous commit.
4ee91bb8a8