Remove -Wno-unknown-pragmas from fusl build

fusl/src/math/fmaf.c

 /* origin: FreeBSD /usr/src/lib/msun/src/s_fmaf.c */
 /*-
  * Copyright (c) 2005-2011 David Schultz <das@FreeBSD.ORG>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 10 matching lines @@
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
 
 #include <fenv.h>
 #include <math.h>
 #include <stdint.h>
+#include "libm.h"
 
 /*
  * Fused multiply-add: Compute x * y + z with a single rounding error.
  *
  * A double has more than twice as much precision than a float, so
  * direct double-precision arithmetic suffices, except where double
  * rounding occurs.
  */
 float fmaf(float x, float y, float z)
 {
-        #pragma STDC FENV_ACCESS ON
+        PRAGMA_STDC_FENV_ACCESS_ON
         double xy, result;
         union {double f; uint64_t i;} u;
         int e;
 
         xy = (double)x * y;
         result = xy + z;
         u.f = result;
         e = u.i>>52 & 0x7ff;
         /* Common case: The double precision result is fine. */
         if ((u.i & 0x1fffffff) != 0x10000000 || /* not a halfway case */
@@ skipping 32 matching lines @@
         double adjusted_result = vxy + z;
         fesetround(FE_TONEAREST);
         if (result == adjusted_result) {
                 u.f = adjusted_result;
                 u.i++;
                 adjusted_result = u.f;
         }
         z = adjusted_result;
         return z;
 }