[cleanup] Fix compiler classes, removing unnecessary copies.

Fixing clang-tidy warning.

Bug: v8:8015
Change-Id: I33858c6f6bb577f39f697a1d3094990a57044fca
Reviewed-on: https://chromium-review.googlesource.com/1228065
Commit-Queue: Florian Sattler <sattlerf@google.com>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55990}

src/compiler/bytecode-analysis.cc

@@ -666,7 +666,7 @@ bool BytecodeAnalysis::ResumeJumpTargetsAreValid() {
       valid = false;
     }
     // Check loops.
-    for (const std::pair<int, LoopInfo>& loop_info : header_to_info_) {
+    for (const std::pair<const int, LoopInfo>& loop_info : header_to_info_) {
       if (!loop_info.second.resume_jump_targets().empty()) {
         PrintF(stderr,
                "Found %zu resume targets at loop at offset %d, but no resume "
@@ -700,7 +700,7 @@ bool BytecodeAnalysis::ResumeJumpTargetsAreValid() {
     valid = false;
   }
   // Check loops.
-  for (const std::pair<int, LoopInfo>& loop_info : header_to_info_) {
+  for (const std::pair<const int, LoopInfo>& loop_info : header_to_info_) {
     if (!ResumeJumpTargetLeavesResolveSuspendIds(
             loop_info.first, loop_info.second.resume_jump_targets(),
             &unresolved_suspend_ids)) {
@@ -714,7 +714,7 @@ bool BytecodeAnalysis::ResumeJumpTargetsAreValid() {
            "Found suspend ids that are not resolved by a final leaf resume "
            "jump:\n");
 
-    for (const std::pair<int, int>& target : unresolved_suspend_ids) {
+    for (const std::pair<const int, int>& target : unresolved_suspend_ids) {
       PrintF(stderr, "  %d -> %d\n", target.first, target.second);
     }
     valid = false;

src/compiler/code-assembler.cc

@@ -1403,8 +1403,8 @@ void CodeAssembler::Branch(SloppyTNode<IntegralT> condition, Label* true_label,
 }
 
 void CodeAssembler::Branch(TNode<BoolT> condition,
-                           std::function<void()> true_body,
-                           std::function<void()> false_body) {
+                           const std::function<void()>& true_body,
+                           const std::function<void()>& false_body) {
   int32_t constant;
   if (ToInt32Constant(condition, constant)) {
     return constant ? true_body() : false_body();
@@ -1421,7 +1421,7 @@ void CodeAssembler::Branch(TNode<BoolT> condition,
 }
 
 void CodeAssembler::Branch(TNode<BoolT> condition, Label* true_label,
-                           std::function<void()> false_body) {
+                           const std::function<void()>& false_body) {
   int32_t constant;
   if (ToInt32Constant(condition, constant)) {
     return constant ? Goto(true_label) : false_body();
@@ -1434,7 +1434,7 @@ void CodeAssembler::Branch(TNode<BoolT> condition, Label* true_label,
 }
 
 void CodeAssembler::Branch(TNode<BoolT> condition,
-                           std::function<void()> true_body,
+                           const std::function<void()>& true_body,
                            Label* false_label) {
   int32_t constant;
   if (ToInt32Constant(condition, constant)) {

src/compiler/code-assembler.h

@@ -780,11 +780,11 @@ class V8_EXPORT_PRIVATE CodeAssembler {
   void Branch(SloppyTNode<IntegralT> condition, Label* true_label,
               Label* false_label);
 
-  void Branch(TNode<BoolT> condition, std::function<void()> true_body,
-              std::function<void()> false_body);
+  void Branch(TNode<BoolT> condition, const std::function<void()>& true_body,
+              const std::function<void()>& false_body);
   void Branch(TNode<BoolT> condition, Label* true_label,
-              std::function<void()> false_body);
-  void Branch(TNode<BoolT> condition, std::function<void()> true_body,
+              const std::function<void()>& false_body);
+  void Branch(TNode<BoolT> condition, const std::function<void()>& true_body,
               Label* false_label);
 
   void Switch(Node* index, Label* default_label, const int32_t* case_values,