[PATCH] Disable uninitialized warning with GCC 4.8

[Stan Shebs]

As with other spots in the code, GCC 4.8 unnecessarily complains about
an uninitialized variable in tanl calcs, so this patch disables.  With
it, the library and sees the usual set of test passes.

Stan

        * sysdeps/ieee754/ldbl-96/k_tanl.c: Include <libc-internal.h>.
        (__kernel_tanl): Ignore uninitialized warnings around use of SIGN.

diff --git a/sysdeps/ieee754/ldbl-96/k_tanl.c b/sysdeps/ieee754/ldbl-96/k_tanl.c
index ae6821d..b7f7869 100644
--- a/sysdeps/ieee754/ldbl-96/k_tanl.c
+++ b/sysdeps/ieee754/ldbl-96/k_tanl.c
@@ -57,6 +57,7 @@
  */

 #include <float.h>
+#include <libc-internal.h>
 #include <math.h>
 #include <math_private.h>
 static const long double
@@ -136,8 +137,19 @@ __kernel_tanl (long double x, long double y, int iy)
     {
       v = (long double) iy;
       w = (v - 2.0 * (x - (w * w / (w + v) - r)));
+      /* SIGN is set for arguments that reach this code, but not
+        otherwise, resulting in warnings that it may be used
+        uninitialized although in the cases where it is used it has
+        always been set.  */
+      DIAG_PUSH_NEEDS_COMMENT;
+#if __GNUC_PREREQ (4, 7)
+      DIAG_IGNORE_NEEDS_COMMENT (4.8, "-Wmaybe-uninitialized");
+#else
+      DIAG_IGNORE_NEEDS_COMMENT (4.8, "-Wuninitialized");
+#endif
       if (sign < 0)
        w = -w;
+      DIAG_POP_NEEDS_COMMENT;
       return w;
     }
   if (iy == 1)