stage2: add more float arithmetic and f80 support

AstGen: Fixed bug where f80 types in source were triggering illegal
behavior.

Value: handle f80 in floating point arithmetic functions.

Value: implement floatRem and floatMod

This commit introduces dependencies on compiler-rt that are not
implemented. Those are a prerequisite to merging this branch.
287ff4ab58Andrew Kelley committed on 2/7/2022, 2:27:54 AMparentfd1284e
4 files changedLine totals unavailable