Remove sun musl fdlibm math library

The libm code from musl wasn't being used since most of these functions
are implemented using x87 which goes faster than a library intended for
risc machines.

test/libc/test.mk

@@ -10,7 +10,6 @@ o/$(MODE)/test/libc:					\
 		o/$(MODE)/test/libc/dns			\
 		o/$(MODE)/test/libc/fmt			\
 		o/$(MODE)/test/libc/intrin		\
-		o/$(MODE)/test/libc/math		\
 		o/$(MODE)/test/libc/mem			\
 		o/$(MODE)/test/libc/nexgen32e		\
 		o/$(MODE)/test/libc/rand		\