Reduce stack usage for overflow checks

This reduces the stack space reserved for overflow checks to 12K, split
into an 8K gap and a 4K protected region.  GC needs over 8K when running
in a stack overflow situation.

Also prevents signal runaway by detecting a signal inside code that
resulted from a signal handler invokation.  And adds a max signal count to
the SignalTest to prevent it running forever.

Also reduces the number of iterations for the InterfaceTest as this was
taking (almost) forever with the --trace option on run-test.

Bug: 15435566

Change-Id: Id4fd46f22d52d42a9eb431ca07948673e8fda694
diff --git a/compiler/optimizing/code_generator_x86_64.cc b/compiler/optimizing/code_generator_x86_64.cc
index e4259f5..c4571ca 100644
--- a/compiler/optimizing/code_generator_x86_64.cc
+++ b/compiler/optimizing/code_generator_x86_64.cc
@@ -209,7 +209,7 @@
   core_spill_mask_ |= (1 << kFakeReturnRegister);
 
   bool skip_overflow_check = IsLeafMethod()
-      && !IsLargeFrame(GetFrameSize(), InstructionSet::kX86_64);
+      && !FrameNeedsStackCheck(GetFrameSize(), InstructionSet::kX86_64);
 
   if (!skip_overflow_check && !kExplicitStackOverflowCheck) {
     __ testq(CpuRegister(RAX), Address(