Jit: Fix for 2793725 SIGSEGV in JIT code cache

r8 was missing from the handler clobber set, and is stepped on by
the handlers for inline string compareto and indexof.

Change-Id: I6e5d6f46b595d638863b27edcc8718157a3e411f
diff --git a/vm/compiler/codegen/arm/RallocUtil.c b/vm/compiler/codegen/arm/RallocUtil.c
index 80ce968..e917995 100644
--- a/vm/compiler/codegen/arm/RallocUtil.c
+++ b/vm/compiler/codegen/arm/RallocUtil.c
@@ -482,6 +482,8 @@
     //TUNING: reduce the set of regs used by handlers.  Only a few need lots.
     dvmCompilerClobberCallRegs(cUnit);
     dvmCompilerClobber(cUnit, r4PC);
+    dvmCompilerClobber(cUnit, r7);
+    dvmCompilerClobber(cUnit, r8);
     dvmCompilerClobber(cUnit, r9);
     dvmCompilerClobber(cUnit, r10);
 }