Minor compiler tuning

Large switch statements were getting bogged down in a linear search.
Added a map for fast lookup (which may also be useful for debug
support).

Change-Id: I00e5956ea7e98ff2c870fb2d3e299e8d4c88f598
diff --git a/src/compiler/codegen/arm/MethodCodegenDriver.cc b/src/compiler/codegen/arm/MethodCodegenDriver.cc
index 77b58ff..6f476f9 100644
--- a/src/compiler/codegen/arm/MethodCodegenDriver.cc
+++ b/src/compiler/codegen/arm/MethodCodegenDriver.cc
@@ -2049,6 +2049,8 @@
         boundaryLIR = newLIR1(cUnit, kArmPseudoDalvikByteCodeBoundary,
                              (int) oatGetDalvikDisassembly(
                              &mir->dalvikInsn, ""));
+        cUnit->boundaryMap.insert(std::make_pair(mir->offset,
+                                 (LIR*)boundaryLIR));
         /* Remember the first LIR for this block */
         if (headLIR == NULL) {
             headLIR = boundaryLIR;