Fix build.

Rather than try to be clever with header files (which didn't work with glibc
for the sim build) let's make Math.copySign have the StrictMath behavior,
and have StrictMath call Math. (The other way round, though it might seem
more logical, wouldn't solve the problem. We already have numerous cases of
StrictMath calling Math anyway.)

Change-Id: Ifff065ddc8fbd5d5f8d4d5b67bc9ac07a719eb00
3 files changed