Remove -Wno-unknown-pragmas from fusl build

fusl/src/math/nearbyint.c

Index: fusl/src/math/nearbyint.c
diff --git a/fusl/src/math/nearbyint.c b/fusl/src/math/nearbyint.c
index f4e8aac4f0118d7d48d1d6a8e4af0fec048ee62a..b1c867f6b729fdaab34d2af15ca98bc8e4d688c0 100644
--- a/fusl/src/math/nearbyint.c
+++ b/fusl/src/math/nearbyint.c
@@ -1,12 +1,13 @@
 #include <fenv.h>
 #include <math.h>
+#include "libm.h"
 
 /* nearbyint is the same as rint, but it must not raise the inexact exception */
 
 double nearbyint(double x)
 {
 #ifdef FE_INEXACT
-	#pragma STDC FENV_ACCESS ON
+	PRAGMA_STDC_FENV_ACCESS_ON
 	int e;
 
 	e = fetestexcept(FE_INEXACT);