[PATCH, alpha]: Fix PR55344, Cross compiling for alpha-linux fails because doesn't exist

[Uros Bizjak]

Hello!

2012-12-09  Uros Bizjak  <ubiz...@gmail.com>

        * config/alpha/linux-unwind.h: Disable when inhibit_libc is defined.

Bootstrapped and regression tested on alphaev68-pc-linux-gnu,
committed to mainline and 4.7.

Uros.

Index: config/alpha/linux-unwind.h
===================================================================
--- config/alpha/linux-unwind.h (revision 194329)
+++ config/alpha/linux-unwind.h (working copy)
@@ -22,6 +22,7 @@
 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 <http://www.gnu.org/licenses/>.  */
 
+#ifndef inhibit_libc
 /* Do code reading to identify a signal frame, and set the frame
    state data appropriately.  See unwind-dw2.c for the structs.  */
 
@@ -97,3 +98,4 @@
          || pc[1] == 0x201f015f))      /* lda $0,NR_rt_sigreturn */
     _Unwind_SetSignalFrame (context, 1);
 }
+#endif