llvmpipe: fix arith-test build on msvc

These functions aren't implemented using plain functions in the MSVC
runtime, so trying to take the function pointers directly cause
compilation errors.

Instead, let's call them from a wrapper-function, and use a
pre-processor define to replace the usage in this case. This makes these
build fine on MSVC.

Reviewed-by: Jesse Natalie <jenatali@microsoft.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7549>

src/gallium/drivers/llvmpipe/lp_test_arit.c

@@ -293,6 +293,27 @@ const float fract_values[] = {
  * Unary test cases.
  */
 
+#ifdef _MSC_VER
+#define WRAP(func) \
+static float \
+wrap_ ## func ## (float x) \
+{ \
+   return func(x); \
+}
+WRAP(expf)
+WRAP(logf)
+WRAP(sinf)
+WRAP(cosf)
+WRAP(floorf)
+WRAP(ceilf)
+#define expf wrap_expf
+#define logf wrap_logf
+#define sinf wrap_sinf
+#define cosf wrap_cosf
+#define floorf wrap_floorf
+#define ceilf wrap_ceilf
+#endif
+
 static const struct unary_test_t
 unary_tests[] = {
    {"abs", &lp_build_abs, &fabsf, sgn_values, ARRAY_SIZE(sgn_values), 20.0 },