[libc] Add implementations of remquo[f|l] and remainder[f|l].

The implementation is not fully standards compliant in the sense that
errno is not set on error, and floating point exceptions are not raised.

Subnormal range and normal range are tested separately in the tests.

Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D86666

GitOrigin-RevId: 8514ecb02d4330bc075b9c8fef77c87810088d2f
24 files changed