Add functions, tests and benchmarks. Fix typos in comments
in expm1 and hypot_386. Fix Acosh domain error in benchmark
test.
R=rsc
CC=golang-dev
https://golang.org/cl/204069
Added special cases to comments for asin.go and fabs.go.
Added Trunc() to floor.go and floor_386.s. Fixed formatting
error in hypot_386.s Added new functions Acosh, Asinh,
Atanh, Copysign, Erf, Erfc, Expm1, and Log1p. Added
386 FPU version of Fmod. Added tests, benchmarks, and
precision to expected results in all_test.go. Edited
makefile so it all compiles.
R=rsc
CC=golang-dev
https://golang.org/cl/195052