Refactor ExternalReference::isolate_address() to not rely on Isolate::Current().

src/mips/macro-assembler-mips.cc

Index: src/mips/macro-assembler-mips.cc
diff --git a/src/mips/macro-assembler-mips.cc b/src/mips/macro-assembler-mips.cc
index 6f9891469e38f24f291146e0a0695b595e180400..f18da1c90b46198109debd97aa1e0519246ce414 100644
--- a/src/mips/macro-assembler-mips.cc
+++ b/src/mips/macro-assembler-mips.cc
@@ -3996,7 +3996,7 @@ void MacroAssembler::CallApiFunctionAndReturn(ExternalReference function,
   mov(s0, v0);
   mov(a0, v0);
   PrepareCallCFunction(1, s1);
-  li(a0, Operand(ExternalReference::isolate_address()));
+  li(a0, Operand(ExternalReference::isolate_address(isolate())));
   CallCFunction(ExternalReference::delete_handle_scope_extensions(isolate()),
       1);
   mov(v0, s0);