Fix has_constant_parameter_count() confusion in LReturn

src/ia32/lithium-codegen-ia32.cc

Index: src/ia32/lithium-codegen-ia32.cc
diff --git a/src/ia32/lithium-codegen-ia32.cc b/src/ia32/lithium-codegen-ia32.cc
index c64a4b0892e763007b80ee49434f278ed4c846fd..d6ffbee4fe6bd65ed6d4e01ddf98f4687cc29e16 100644
--- a/src/ia32/lithium-codegen-ia32.cc
+++ b/src/ia32/lithium-codegen-ia32.cc
@@ -2753,6 +2753,7 @@ void LCodeGen::EmitReturn(LReturn* instr, bool dynamic_frame_alignment) {
     }
     __ Ret((parameter_count + extra_value_count) * kPointerSize, ecx);
   } else {
+    DCHECK(info()->IsStub());  // Functions would need to drop one more value.
     Register reg = ToRegister(instr->parameter_count());
     // The argument count parameter is a smi
     __ SmiUntag(reg);
@@ -2770,6 +2771,7 @@ void LCodeGen::EmitReturn(LReturn* instr, bool dynamic_frame_alignment) {
     if (dynamic_frame_alignment) {
       __ inc(reg);  // 1 more for alignment
     }
+
     __ shl(reg, kPointerSizeLog2);
     __ add(esp, reg);
     __ jmp(return_addr_reg);