Add compiler stats, fix super call slow path

Add statistics of when the compiler framework has allowed AOT
compilation to be optimistic.
Fix bug that was forcing many calls to be unnecessarily slow path.

Change-Id: I8f0f6ab4738b11161855cf0dc424babed774c998
diff --git a/src/compiler/CompilerIR.h b/src/compiler/CompilerIR.h
index ade478f..9a992a1 100644
--- a/src/compiler/CompilerIR.h
+++ b/src/compiler/CompilerIR.h
@@ -212,7 +212,7 @@
     int numInsts;
     int numBlocks;
     GrowableList blockList;
-    const Compiler* compiler;           // Compiler driving this compiler
+    Compiler* compiler;            // Compiler driving this compiler
     ClassLinker* class_linker;     // Linker to resolve fields and methods
     const DexFile* dex_file;       // DexFile containing the method being compiled
     DexCache* dex_cache;           // DexFile's corresponding cache