Re-enable tests with the optimizing compiler.

Tests run ok on my host/target. I reverted the move to
using thumb2, because tests were crashing. But I could not
reproduce file limits issues.

Make SignalTest as crashing for optimizing. We need to implement
stack overflow checks.

Change-Id: Ieda575501eaf30af7aaa2c44e71544c9c467c24f
diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index a8ee6c0..f624f3c 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -691,7 +691,8 @@
 
 void InstructionCodeGeneratorX86::VisitInvokeStatic(HInvokeStatic* invoke) {
   Register temp = invoke->GetLocations()->GetTemp(0).AsX86().AsCpuRegister();
-  size_t index_in_cache = mirror::Array::DataOffset(sizeof(mirror::Object*)).Int32Value() +
+  uint32_t heap_reference_size = sizeof(mirror::HeapReference<mirror::Object>);
+  size_t index_in_cache = mirror::Array::DataOffset(heap_reference_size).Int32Value() +
       invoke->GetIndexInDexCache() * kX86WordSize;
 
   // TODO: Implement all kinds of calls: