This fixes PR bootstrap/43964, a 4.6 bootstrap failure on ARM
and a regression from the PR target/42895 fix in r158911.
The issue is that r158911 wrapped a block of code in ira-color.c
with an #ifndef HONOR_REG_ALLOC_ORDER, causing two local variables
to become unused in that case.  Stage 2 compiles with -Wall -Werror
by default, causing a compile failure on ira-color.c in stage 2.

Fixed by moving the declarations of these local variables inside
a similar #ifndef HONOR_REG_ALLOC_ORDER.  I considered sinking
the declarations into the block using them instead, but most of
ira-color.c is not written in that style.

Bootstrapped successfully on armv5tel-unknown-linux-gnueabi and
i686-pc-linux-gnu; the first target defines HONOR_REG_ALLOC_ORDER
and the second one does not.

Ok for trunk? (I don't have svn write access.)

gcc/

2010-05-03  Mikael Pettersson  <mikpe@it.uu.se>

	PR bootstrap/43964
	* ira-color.c (assign_hard_reg): Declare rclass and add_cost
	only if HONOR_REG_ALLOC_ORDER is not defined.

--- gcc-4.6-20100501/gcc/ira-color.c.~1~	2010-04-29 23:37:01.000000000 +0200
+++ gcc-4.6-20100501/gcc/ira-color.c	2010-05-03 11:43:18.000000000 +0200
@@ -441,14 +441,18 @@ assign_hard_reg (ira_allocno_t allocno, 
 {
   HARD_REG_SET conflicting_regs;
   int i, j, k, hard_regno, best_hard_regno, class_size;
-  int cost, mem_cost, min_cost, full_cost, min_full_cost, add_cost;
+  int cost, mem_cost, min_cost, full_cost, min_full_cost;
   int *a_costs;
   int *conflict_costs;
-  enum reg_class cover_class, rclass, conflict_cover_class;
+  enum reg_class cover_class, conflict_cover_class;
   enum machine_mode mode;
   ira_allocno_t a, conflict_allocno;
   ira_allocno_conflict_iterator aci;
   static int costs[FIRST_PSEUDO_REGISTER], full_costs[FIRST_PSEUDO_REGISTER];
+#ifndef HONOR_REG_ALLOC_ORDER
+  enum reg_class rclass;
+  int add_cost;
+#endif
 #ifdef STACK_REGS
   bool no_stack_reg_p;
 #endif