Emit warnings when linking against imprecise math functions

Change-Id: I3da7b8396a64d7899fcb89452c879806a8a511ff
Fix modf* tests

Use a value that can be exactly represented.

Change-Id: Idf3b1db5e6042fb49c1f591f25f9eee656659ece
Merge "Fix modf* tests"
Merge "Emit warnings when linking against imprecise math functions"
auto-merger: merge in from aosp/master