[ARC] Add ARCOptAddrMode pass to generate postincrement loads/stores.

Build on newly introduced ARC postincrement loads/stores from r356200.

Patch By Denis Antrushin! <denis@synopsys.com>

Differential Revision: https://reviews.llvm.org/D59409

llvm-svn: 356606
diff --git a/llvm/lib/Target/ARC/ARCTargetMachine.cpp b/llvm/lib/Target/ARC/ARCTargetMachine.cpp
index 2476d40..ed88cf7 100644
--- a/llvm/lib/Target/ARC/ARCTargetMachine.cpp
+++ b/llvm/lib/Target/ARC/ARCTargetMachine.cpp
@@ -74,7 +74,10 @@
 
 void ARCPassConfig::addPreEmitPass() { addPass(createARCBranchFinalizePass()); }
 
-void ARCPassConfig::addPreRegAlloc() { addPass(createARCExpandPseudosPass()); }
+void ARCPassConfig::addPreRegAlloc() {
+    addPass(createARCExpandPseudosPass());
+    addPass(createARCOptAddrMode());
+}
 
 // Force static initialization.
 extern "C" void LLVMInitializeARCTarget() {