MIPS: Fix assertion-fail on cacheflush from generated code.

Fix a mips-specific CallCFunction assertion, when checking for valid
frames on the stack. We fake it with AllowExternalCallThatCantCauseGC().

Landing http://codereview.chromium.org/7932010/ for Paul Lind.


git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9315 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/macro-assembler-mips.cc

@@ -821,6 +821,7 @@ void MacroAssembler::MultiPopReversedFPU(RegList regs) {
 void MacroAssembler::FlushICache(Register address, unsigned instructions) {
   RegList saved_regs = kJSCallerSaved | ra.bit();
   MultiPush(saved_regs);
+  AllowExternalCallThatCantCauseGC scope(this);
 
   // Save to a0 in case address == t0.
   Move(a0, address);