Subzero: Add locking to prepare for multithreaded translation.

src/IceTargetLoweringX8632.cpp

Index: src/IceTargetLoweringX8632.cpp
diff --git a/src/IceTargetLoweringX8632.cpp b/src/IceTargetLoweringX8632.cpp
index f1b746f793cb81cdfe918ca7278964f4da9a4681..c1fd08b0f47c5e52aee6acad7e9d02cf2ad2764f 100644
--- a/src/IceTargetLoweringX8632.cpp
+++ b/src/IceTargetLoweringX8632.cpp
@@ -898,6 +898,7 @@ void TargetX8632::addProlog(CfgNode *Node) {
   }
 
   if (ALLOW_DUMP && Func->getContext()->isVerbose(IceV_Frame)) {
+    OstreamLocker L(Func->getContext());
     Ostream &Str = Func->getContext()->getStrDump();
 
     Str << "Stack layout:\n";
@@ -1023,6 +1024,7 @@ template <typename T> void TargetX8632::emitConstantPool() const {
 void TargetX8632::emitConstants() const {
   // No need to emit constants from the int pool since (for x86) they
   // are embedded as immediates in the instructions, just emit float/double.
+  OstreamLocker L(Ctx);
   if (Ctx->getFlags().UseELFWriter) {
     ELFObjectWriter *Writer = Ctx->getObjectWriter();
     Writer->writeConstantPool<ConstantFloat>(IceType_f32);
@@ -3567,6 +3569,7 @@ void dumpAddressOpt(const Cfg *Func, const Variable *Base,
     return;
   if (!Func->getContext()->isVerbose(IceV_AddrOpt))
     return;
+  OstreamLocker L(Func->getContext());
   Ostream &Str = Func->getContext()->getStrDump();
   Str << "Instruction: ";
   Reason->dumpDecorated(Func);
@@ -3738,6 +3741,7 @@ void computeAddressOpt(Cfg *Func, const Inst *Instr, Variable *&Base,
                        Variable *&Index, uint16_t &Shift, int32_t &Offset) {
   Func->resetCurrentNode();
   if (Func->getContext()->isVerbose(IceV_AddrOpt)) {
+    OstreamLocker L(Func->getContext());
     Ostream &Str = Func->getContext()->getStrDump();
     Str << "\nStarting computeAddressOpt for instruction:\n  ";
     Instr->dumpDecorated(Func);
@@ -4579,6 +4583,7 @@ void TargetX8632::makeRandomRegisterPermutation(
   assert(NumShuffled + NumPreserved == RegX8632::Reg_NUM);
 
   if (Func->getContext()->isVerbose(IceV_Random)) {
+    OstreamLocker L(Func->getContext());
     Ostream &Str = Func->getContext()->getStrDump();
     Str << "Register equivalence classes:\n";
     for (auto I : EquivalenceClasses) {