MIPS: Refine 'r6 compact branch optimization.'

src/mips64/assembler-mips64.cc

Index: src/mips64/assembler-mips64.cc
diff --git a/src/mips64/assembler-mips64.cc b/src/mips64/assembler-mips64.cc
index 9c313a18d696eecb165bcc095da403ce663f24b3..f0d3eba6b67e1f3be8d53f481d54fcaae3f42963 100644
--- a/src/mips64/assembler-mips64.cc
+++ b/src/mips64/assembler-mips64.cc
@@ -3270,10 +3270,9 @@ void Assembler::CheckTrampolinePool() {
         bc(&after_pool);
       } else {
         b(&after_pool);
-        nop();
       }
+      nop();
 
-      EmitForbiddenSlotInstruction();
       int pool_start = pc_offset();
       for (int i = 0; i < unbound_labels_count_; i++) {
         { BlockGrowBufferScope block_buf_growth(this);