Stack overflow checks and NPE checks for optimizing.

Change-Id: I59e97448bf29778769b79b51ee4ea43f43493d96
diff --git a/compiler/utils/x86/assembler_x86.cc b/compiler/utils/x86/assembler_x86.cc
index 56c6536..b6a5c20 100644
--- a/compiler/utils/x86/assembler_x86.cc
+++ b/compiler/utils/x86/assembler_x86.cc
@@ -806,6 +806,13 @@
 }
 
 
+void X86Assembler::testl(Register reg, const Address& address) {
+  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
+  EmitUint8(0x85);
+  EmitOperand(reg, address);
+}
+
+
 void X86Assembler::testl(Register reg, const Immediate& immediate) {
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
   // For registers that have a byte variant (EAX, EBX, ECX, and EDX)