[RFC] sh-tdep.c: Don't fetch FPSCR register if it doesn't exist

[Kevin Buettner <kevinb@redhat.com>]

The patch below fixes 119 failures for the default sh-elf multilib (using
sh-sim.)  I can post a list if there's interest in seeing them.

Comments?  Is there a better way to test for the existence of a register?

Kevin

	* sh-tdep.c (sh_frame_cache): Don't fetch the FPSCR register
	unless it exists for this architecture.

Index: sh-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/sh-tdep.c,v
retrieving revision 1.239
diff -u -p -r1.239 sh-tdep.c
--- sh-tdep.c	27 Feb 2012 16:40:48 -0000	1.239
+++ sh-tdep.c	1 Mar 2012 00:31:31 -0000
@@ -2553,7 +2553,12 @@ sh_frame_cache (struct frame_info *this_
   if (cache->pc != 0)
     {
       ULONGEST fpscr;
-      fpscr = get_frame_register_unsigned (this_frame, FPSCR_REGNUM);
+      const char *fpscr_name = gdbarch_register_name (gdbarch, FPSCR_REGNUM);
+
+      if (fpscr_name && fpscr_name[0])
+	fpscr = get_frame_register_unsigned (this_frame, FPSCR_REGNUM);
+      else
+	fpscr = 0;
       sh_analyze_prologue (gdbarch, cache->pc, current_pc, cache, fpscr);
     }