[turbofan] Enable tail calls for %_CallFunction.

src/compiler/mips/code-generator-mips.cc

Index: src/compiler/mips/code-generator-mips.cc
diff --git a/src/compiler/mips/code-generator-mips.cc b/src/compiler/mips/code-generator-mips.cc
index a7806ccae236c2ee0e83399386915b1480f9d299..4d87f2c2434c331db521d7b71e07db2d80bf6fc0 100644
--- a/src/compiler/mips/code-generator-mips.cc
+++ b/src/compiler/mips/code-generator-mips.cc
@@ -399,10 +399,6 @@ void CodeGenerator::AssembleDeconstructActivationRecord() {
   int stack_slots = frame()->GetSpillSlotCount();
   if (descriptor->IsJSFunctionCall() || stack_slots > 0) {
     __ LeaveFrame(StackFrame::MANUAL);
-    int pop_count = descriptor->IsJSFunctionCall()
-                        ? static_cast<int>(descriptor->JSParameterCount())
-                        : 0;
-    __ Drop(pop_count);
   }
 }
 
@@ -1157,8 +1153,14 @@ void CodeGenerator::AssembleReturn() {
       __ Pop(ra, fp);
       int pop_count = descriptor->IsJSFunctionCall()
                           ? static_cast<int>(descriptor->JSParameterCount())
-                          : 0;
-      __ DropAndRet(pop_count);
+                          : (info()->IsStub()
+                                 ? info()->code_stub()->GetStackParameterCount()
+                                 : 0);
+      if (pop_count != 0) {
+        __ DropAndRet(pop_count);
+      } else {
+        __ Ret();
+      }
     }
   } else {
     __ Ret();