[libc] Make GPU libm use generic implementations (#98014)

Summary:
This patch moves a lot of the old vendor implementations to the new
generic math functions. Previously a lot of these were done through the
vendor functions, but the long term goal is to completely phase these
out. In order to make the tests pass I had to disable exceptions so they
only perform functional tests.

Author: jhuber6

libc/include/llvm-libc-macros/math-macros.h

@@ -41,12 +41,10 @@
 #define FP_LLOGBNAN LONG_MAX
 #endif
 
-#ifdef __FAST_MATH__
+#if defined(__NVPTX__) || defined(__AMDGPU__) || defined(__FAST_MATH__)
 #define math_errhandling 0
 #elif defined(__NO_MATH_ERRNO__)
 #define math_errhandling (MATH_ERREXCEPT)
-#elif defined(__NVPTX__) || defined(__AMDGPU__)
-#define math_errhandling (MATH_ERRNO)
 #else
 #define math_errhandling (MATH_ERRNO | MATH_ERREXCEPT)
 #endif