Migrate most uses of Isolate::current_zone to Thread::zone.

runtime/vm/il_printer.cc

Index: runtime/vm/il_printer.cc
diff --git a/runtime/vm/il_printer.cc b/runtime/vm/il_printer.cc
index 0d7914989d70d1d02cecba67442a02efd41b9142..6a5ce9073112af1c3382df29d7b16352b888d2af 100644
--- a/runtime/vm/il_printer.cc
+++ b/runtime/vm/il_printer.cc
@@ -180,7 +180,7 @@ const char* CompileType::ToCString() const {
   char buffer[1024];
   BufferFormatter f(buffer, sizeof(buffer));
   PrintTo(&f);
-  return Isolate::Current()->current_zone()->MakeCopyOfString(buffer);
+  return Thread::Current()->zone()->MakeCopyOfString(buffer);
 }
 
 
@@ -247,7 +247,7 @@ const char* Instruction::ToCString() const {
   char buffer[1024];
   BufferFormatter f(buffer, sizeof(buffer));
   PrintTo(&f);
-  return Isolate::Current()->current_zone()->MakeCopyOfString(buffer);
+  return Thread::Current()->zone()->MakeCopyOfString(buffer);
 }
 
 
@@ -321,7 +321,7 @@ void ConstantInstr::PrintOperandsTo(BufferFormatter* f) const {
     f->Print("#%s", cstr);
   } else {
     const intptr_t pos = new_line - cstr;
-    char* buffer = Isolate::Current()->current_zone()->Alloc<char>(pos + 1);
+    char* buffer = Thread::Current()->zone()->Alloc<char>(pos + 1);
     strncpy(buffer, cstr, pos);
     buffer[pos] = '\0';
     f->Print("#%s\\n...", buffer);
@@ -351,7 +351,7 @@ const char* Range::ToCString(const Range* range) {
   char buffer[256];
   BufferFormatter f(buffer, sizeof(buffer));
   range->PrintTo(&f);
-  return Isolate::Current()->current_zone()->MakeCopyOfString(buffer);
+  return Thread::Current()->zone()->MakeCopyOfString(buffer);
 }
 
 
@@ -382,7 +382,7 @@ const char* RangeBoundary::ToCString() const {
   char buffer[256];
   BufferFormatter f(buffer, sizeof(buffer));
   PrintTo(&f);
-  return Isolate::Current()->current_zone()->MakeCopyOfString(buffer);
+  return Thread::Current()->zone()->MakeCopyOfString(buffer);
 }
 
 
@@ -1210,7 +1210,7 @@ const char* Environment::ToCString() const {
   char buffer[1024];
   BufferFormatter bf(buffer, 1024);
   PrintTo(&bf);
-  return Isolate::Current()->current_zone()->MakeCopyOfString(buffer);
+  return Thread::Current()->zone()->MakeCopyOfString(buffer);
 }
 
 }  // namespace dart