Rewrite the compiler interface for CompilerDriver.

Change-Id: I15fa9afe7ffb7283ebda8d788a1e02793e3f75a6
diff --git a/compiler/dex/mir_optimization.cc b/compiler/dex/mir_optimization.cc
index 209ed3d..b91ef28 100644
--- a/compiler/dex/mir_optimization.cc
+++ b/compiler/dex/mir_optimization.cc
@@ -406,7 +406,7 @@
       // Is this the select pattern?
       // TODO: flesh out support for Mips.  NOTE: llvm's select op doesn't quite work here.
       // TUNING: expand to support IF_xx compare & branches
-      if ((cu_->compiler_backend != kPortable) &&
+      if (cu_->compiler_backend->IsPortable() &&
           (cu_->instruction_set == kThumb2 || cu_->instruction_set == kX86) &&
           ((mir->dalvikInsn.opcode == Instruction::IF_EQZ) ||
           (mir->dalvikInsn.opcode == Instruction::IF_NEZ))) {