Bug 1553958 - Make JumpTarget.offset default value to invalid offset. r=jorendorff

Differential Revision: https://phabricator.services.mozilla.com/D32401

--HG--
extra : moz-landing-system : lando

js/src/frontend/BytecodeControlStructures.h

@@ -121,14 +121,14 @@ class LoopControl : public BreakableControl {
   JumpList entryJump_;
 
   // The bytecode offset of JSOP_LOOPHEAD.
-  JumpTarget head_ = {BytecodeOffset::invalidOffset()};
+  JumpTarget head_;
 
   // The target of break statement jumps.
-  JumpTarget breakTarget_ = {BytecodeOffset::invalidOffset()};
+  JumpTarget breakTarget_;
 
   // The target of continue statement jumps, e.g., the update portion of a
   // for(;;) loop.
-  JumpTarget continueTarget_ = {BytecodeOffset::invalidOffset()};
+  JumpTarget continueTarget_;
 
   // Stack depth when this loop was pushed on the control stack.
   int32_t stackDepth_;

js/src/frontend/BytecodeEmitter.cpp

@@ -6580,7 +6580,7 @@ bool BytecodeEmitter::emitYieldStar(ParseNode* iter) {
   {
     // goto tryStart;
     JumpList beq;
-    JumpTarget breakTarget = {BytecodeOffset::invalidOffset()};
+    JumpTarget breakTarget;
     if (!emitBackwardJump(JSOP_GOTO, tryStart, &beq, &breakTarget)) {
       //            [stack] NEXT ITER RESULT
       return false;

js/src/frontend/BytecodeSection.h

@@ -252,7 +252,7 @@ class BytecodeSection {
   // ---- Jump ----
 
   // Last jump target emitted.
-  JumpTarget lastTarget_ = {BytecodeOffset::invalidOffset()};
+  JumpTarget lastTarget_;
 
   // ---- Stack ----
 

js/src/frontend/JumpList.h

@@ -55,7 +55,7 @@ namespace frontend {
 
 // Offset of a jump target instruction, used for patching jump instructions.
 struct JumpTarget {
-  BytecodeOffset offset;
+  BytecodeOffset offset = BytecodeOffset::invalidOffset();
 };
 
 struct JumpList {

js/src/frontend/SwitchEmitter.h

@@ -318,7 +318,7 @@ class MOZ_STACK_CLASS SwitchEmitter {
   BytecodeOffset lastCaseOffset_;
 
   // Bytecode offset of the JSOP_JUMPTARGET for default body.
-  JumpTarget defaultJumpTargetOffset_ = {BytecodeOffset::invalidOffset()};
+  JumpTarget defaultJumpTargetOffset_;
 
   // Bytecode offset of the JSOP_DEFAULT.
   JumpList condSwitchDefaultOffset_;