Support unboxed input to indirect goto instruction.

runtime/vm/intermediate_language_ia32.cc

Index: runtime/vm/intermediate_language_ia32.cc
diff --git a/runtime/vm/intermediate_language_ia32.cc b/runtime/vm/intermediate_language_ia32.cc
index 74dab5e50819dfcbb284d7ad15ff3069506716bf..79978e9e4f41325a0cb617b83290a67c9cfb7856 100644
--- a/runtime/vm/intermediate_language_ia32.cc
+++ b/runtime/vm/intermediate_language_ia32.cc
@@ -6557,7 +6557,9 @@ void IndirectGotoInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
 
   // Add the offset.
   Register offset_reg = locs()->in(0).reg();
-  __ SmiUntag(offset_reg);
+  if (offset()->definition()->representation() == kTagged) {
+    __ SmiUntag(offset_reg);
+  }
   __ addl(target_address_reg, offset_reg);
 
   // Jump to the absolute address.