Darwin, crts: Fix a build warning.

We have a shim crt for Darwin10 that implements functionality
missing in libSystem. Provide this with a prototype to silence the
warning about this.

libgcc/ChangeLog:

	* config/darwin10-unwind-find-enc-func.c: Include libgcc_tm.h.
	* config/i386/darwin-lib.h: Declare Darwin10 crt function.

Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>

libgcc/config/darwin10-unwind-find-enc-func.c

@@ -1,6 +1,7 @@
 #include "tconfig.h"
 #include "tsystem.h"
 #include "unwind-dw2-fde.h"
+#include "libgcc_tm.h"
 
 void *
 _darwin10_Unwind_FindEnclosingFunction (void *pc)

libgcc/config/i386/darwin-lib.h

@@ -30,3 +30,5 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #define DECLARE_LIBRARY_RENAMES \
   asm(".text; ___divdc3: jmp ___ieee_divdc3 ; .globl ___divdc3");
 #endif
+
+extern void * _darwin10_Unwind_FindEnclosingFunction (void *);