Cleanup and minor fixes in win32/tcc/tcc_libm.h: truncf(), cbrtf(), exp2f(), log2f(), scalbln*()
Cleanup and minor fixes in win32/tcc/tcc_libm.h: truncf(), cbrtf(), exp2f(), log2f(), scalbln*()

mirror/tinycc,mingodad/tinycc,mirror/tinycc,mingodad/tinycc,mingodad/tinycc,mirror/tinycc,mingodad/tinycc,mirror/tinycc