Quick compiler - packed switch support

Add support for PACKED_SWITCH.  Uses the stock llvm switch operator
plus additional metadata for the Quick path that the portable path
may freely ignore.

Change-Id: I3f7cbf9d441d4cc53bf188beeb94d4178fef3e07
diff --git a/src/compiler/Compiler.h b/src/compiler/Compiler.h
index 4d749ce..088768b 100644
--- a/src/compiler/Compiler.h
+++ b/src/compiler/Compiler.h
@@ -197,6 +197,7 @@
 bool oatIsFpReg(int reg);
 uint32_t oatFpRegMask(void);
 void oatReplaceSpecialChars(std::string& str);
+BasicBlock* oatFindBlock(CompilationUnit* cUnit, unsigned int codeOffset);
 
 }  // namespace art