compiler: rollback "avoid negative zero in float constants"
It uses functions that are not available in MPFR 2.4.2, which is the
current version supported by GCC.
Original change description:
compiler: avoid negative zero in float constants
Check for negative numbers with very small magnitudes that will round
to negative zero, and force them to positive zero instead.
This implements the spec clarification in https://golang.org/cl/14727.
The test is in https://golang.org/cl/91895.
Fixes golang/go#12621
Updates golang/go#12621
Change-Id: Ibe89ba756c044bef7796934dbb01550db041dced
Reviewed-on: https://go-review.googlesource.com/92055
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2 files changed
