MIPS: Update an outdated comment in the CEntryStub.

src/mips/code-stubs-mips.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 3524 matching lines @@
   __ mov(a0, s0);
   __ mov(a1, s1);
 
   // We are calling compiled C/C++ code. a0 and a1 hold our two arguments. We
   // also need to reserve the 4 argument slots on the stack.
 
   __ AssertStackIsAligned();
 
   __ li(a2, Operand(ExternalReference::isolate_address()));
 
-  // From arm version of this function:
-  // TODO(1242173): To let the GC traverse the return address of the exit
-  // frames, we need to know where the return address is. Right now,
-  // we push it on the stack to be able to find it again, but we never
-  // restore from it in case of changes, which makes it impossible to
-  // support moving the C entry code stub. This should be fixed, but currently
-  // this is OK because the CEntryStub gets generated so early in the V8 boot
-  // sequence that it is not moving ever.
-
+  // To let the GC traverse the return address of the exit frames, we need to
+  // know where the return address is. The CEntryStub is unmovable, so
+  // we can store the address on the stack to be able to find it again and
+  // we never have to restore it, because it will not change.
   { Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm);
     // This branch-and-link sequence is needed to find the current PC on mips,
     // saved to the ra register.
     // Use masm-> here instead of the double-underscore macro since extra
     // coverage code can interfere with the proper calculation of ra.
     Label find_ra;
     masm->bal(&find_ra);  // bal exposes branch delay slot.
     masm->nop();  // Branch delay slot nop.
     masm->bind(&find_ra);
 
@@ skipping 3090 matching lines @@
   __ mov(result, zero_reg);
   __ Ret();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS