Implement RRI and RRI8 variants of IMUL.

Also make a few UNIMPLEMENTEDs slightly more revealing.

Change-Id: I4471e7ffb84523146611bbd4c7527fb7e183e894
diff --git a/src/compiler/codegen/x86/X86/Gen.cc b/src/compiler/codegen/x86/X86/Gen.cc
index f2dbc11..ffc5952 100644
--- a/src/compiler/codegen/x86/X86/Gen.cc
+++ b/src/compiler/codegen/x86/X86/Gen.cc
@@ -168,7 +168,7 @@
 
 void genNegFloat(CompilationUnit *cUnit, RegLocation rlDest, RegLocation rlSrc)
 {
-    UNIMPLEMENTED(WARNING) << "genNegFloat";
+    UNIMPLEMENTED(WARNING) << "genNegFloat " << PrettyMethod(cUnit->method_idx, *cUnit->dex_file);
     newLIR0(cUnit, kX86Bkpt);
 #if 0
     RegLocation rlResult;
@@ -182,7 +182,7 @@
 
 void genNegDouble(CompilationUnit *cUnit, RegLocation rlDest, RegLocation rlSrc)
 {
-    UNIMPLEMENTED(WARNING) << "genNegDouble";
+    UNIMPLEMENTED(WARNING) << "genNegDouble" << PrettyMethod(cUnit->method_idx, *cUnit->dex_file);
     newLIR0(cUnit, kX86Bkpt);
 #if 0
     RegLocation rlResult;