[libc] Combine all math differential fuzzers into one target.

Also added diffing of a few more math functions. Combining the diff check
for all of these functions helps us meet the OSS fuzz bar of a minimum of
100 program edges.

Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D91817

GitOrigin-RevId: 4766a86cf2f9ac47b1a0288fde84dc74f55b3f11
13 files changed