MIPS: Fix unbounded label counter.

TEST=mjsunit/asm/embenchen/zlib
BUG=

Review-Url: https://codereview.chromium.org/1925543003
Cr-Commit-Position: refs/heads/master@{#35854}

src/mips/assembler-mips.cc

@@ -2959,6 +2959,7 @@ void Assembler::dd(Label* label) {
     data = reinterpret_cast<uint32_t>(buffer_ + label->pos());
   } else {
     data = jump_address(label);
+    unbound_labels_count_++;
     internal_reference_positions_.insert(label->pos());
   }
   RecordRelocInfo(RelocInfo::INTERNAL_REFERENCE);

src/mips/assembler-mips.h

@@ -1161,6 +1161,8 @@ class Assembler : public AssemblerBase {
 
   bool IsPrevInstrCompactBranch() { return prev_instr_compact_branch_; }
 
+  inline int UnboundLabelsCount() { return unbound_labels_count_; }
+
  protected:
   // Load Scaled Address instruction.
   void lsa(Register rd, Register rt, Register rs, uint8_t sa);

src/mips64/assembler-mips64.cc

@@ -3212,6 +3212,7 @@ void Assembler::dd(Label* label) {
     data = reinterpret_cast<uint64_t>(buffer_ + label->pos());
   } else {
     data = jump_address(label);
+    unbound_labels_count_++;
     internal_reference_positions_.insert(label->pos());
   }
   RecordRelocInfo(RelocInfo::INTERNAL_REFERENCE);

src/mips64/assembler-mips64.h

@@ -1215,6 +1215,8 @@ class Assembler : public AssemblerBase {
 
   bool IsPrevInstrCompactBranch() { return prev_instr_compact_branch_; }
 
+  inline int UnboundLabelsCount() { return unbound_labels_count_; }
+
  protected:
   // Load Scaled Address instructions.
   void lsa(Register rd, Register rt, Register rs, uint8_t sa);

test/cctest/test-assembler-mips.cc

@@ -3191,6 +3191,8 @@ TEST(jump_tables1) {
   __ jr(ra);
   __ nop();
 
+  CHECK_EQ(assm.UnboundLabelsCount(), 0);
+
   CodeDesc desc;
   assm.GetCode(&desc);
   Handle<Code> code = isolate->factory()->NewCode(

test/cctest/test-assembler-mips64.cc

@@ -3315,6 +3315,8 @@ TEST(jump_tables1) {
   __ jr(ra);
   __ nop();
 
+  CHECK_EQ(assm.UnboundLabelsCount(), 0);
+
   CodeDesc desc;
   assm.GetCode(&desc);
   Handle<Code> code = isolate->factory()->NewCode(