MIPS: [runtime] Unify and simplify how frames are marked.

src/mips64/deoptimizer-mips64.cc

Index: src/mips64/deoptimizer-mips64.cc
diff --git a/src/mips64/deoptimizer-mips64.cc b/src/mips64/deoptimizer-mips64.cc
index ec610f02819aa7472e98a191b3a36de6513b4bb7..b463875746a9aadb6748a6b8bbdcb1f36959842d 100644
--- a/src/mips64/deoptimizer-mips64.cc
+++ b/src/mips64/deoptimizer-mips64.cc
@@ -161,9 +161,14 @@ void Deoptimizer::TableEntryGenerator::Generate() {
 
   // Allocate a new deoptimizer object.
   __ PrepareCallCFunction(6, a5);
-  // Pass six arguments, according to O32 or n64 ABI. a0..a3 are same for both.
-  __ li(a1, Operand(type()));  // bailout type,
+  // Pass six arguments, according to n64 ABI.
+  __ mov(a0, zero_reg);
+  Label context_check;
+  __ ld(a1, MemOperand(fp, CommonFrameConstants::kContextOrFrameTypeOffset));
+  __ JumpIfSmi(a1, &context_check);
   __ ld(a0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
+  __ bind(&context_check);
+  __ li(a1, Operand(type()));  // Bailout type.
   // a2: bailout id already loaded.
   // a3: code address or 0 already loaded.
   // a4: already has fp-to-sp delta.