MIPS: Fix unbounded label counter.

src/mips/assembler-mips.h

Index: src/mips/assembler-mips.h
diff --git a/src/mips/assembler-mips.h b/src/mips/assembler-mips.h
index ed5cbf8bf2ee2fd6844572d1b4097f8f41e72718..37f32fa1361f082d3e30438477b8646528c59726 100644
--- a/src/mips/assembler-mips.h
+++ b/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);