Bug 687683: Some random comment fixes I came across. r=jorendorff

js/src/methodjit/Compiler.cpp

@@ -3423,7 +3423,7 @@ mjit::Compiler::emitReturn(FrameEntry *fe)
     }
 
     /*
-     * Outside the mjit, activation objects are put by StackSpace::pop*
+     * Outside the mjit, activation objects are put by ContextStack::pop*
      * members. For JSOP_RETURN, the interpreter only calls popInlineFrame if
      * fp != entryFrame since the VM protocol is that Invoke/Execute are
      * responsible for pushing/popping the initial frame. The mjit does not

js/src/methodjit/MethodJIT.h

@@ -462,10 +462,21 @@ class JaegerCompartment {
         return result;
     }
 
+    /*
+     * To force the top StackFrame in a VMFrame to return, when that VMFrame
+     * has called an extern "C" function (say, js_InternalThrow or
+     * js_InternalInterpret), change the extern "C" function's return address
+     * to the value this method returns.
+     */
     void *forceReturnFromExternC() const {
         return JS_FUNC_TO_DATA_PTR(void *, trampolines.forceReturn);
     }
 
+    /*
+     * To force the top StackFrame in a VMFrame to return, when that VMFrame has
+     * called a fastcall function (say, most stubs:: functions), change the
+     * fastcall function's return address to the value this method returns.
+     */
     void *forceReturnFromFastCall() const {
 #if (defined(JS_NO_FASTCALL) && defined(JS_CPU_X86)) || defined(_WIN64)
         return JS_FUNC_TO_DATA_PTR(void *, trampolines.forceReturnFast);