Testsuite: Fix fp-int-convert-timode-1.c testism.

The test fp-int-convert-timode-1.c uses FE_TONEAREST without
actually checking if the target has defined it.

Like the rest of the tests I now add a check to see if the target
has actually implemented it.

This fixed Arm newlib target failures.

Regtested on aarch64-none-elf and aarch64_be-none-elf and no issues.

Committed under the GCC obvious rules.

gcc/testsuite/ChangeLog:

	* gcc.dg/torture/fp-int-convert-timode-1.c: Add check for FE_TONEAREST.

From-SVN: r278552

gcc/testsuite/ChangeLog

+2019-11-21  Tamar Christina  <tamar.christina@arm.com>
+
+	* gcc.dg/torture/fp-int-convert-timode-1.c: Add check for FE_TONEAREST.
+
 2019-11-21  Richard Sandiford  <richard.sandiford@arm.com>
 
 	* gcc.target/aarch64/sve2/whilerw_1.c: Add -fno-vect-cost-model.

gcc/testsuite/gcc.dg/torture/fp-int-convert-timode-1.c

@@ -11,6 +11,7 @@
 int
 main (void)
 {
+#ifdef FE_TONEAREST
   volatile unsigned long long h = 0x8000000000000000LL;
   volatile unsigned long long l = 0xdLL;
   volatile unsigned __int128 u128 = (((unsigned __int128) h) << 64) | l;
@@ -22,5 +23,6 @@ main (void)
   double ds = s128;
   if (ds != -0x1p+127)
     abort ();
+#endif
   exit (0);
 }