[Isolates] Convert more static data either to read-only or to per-isolate.

src/profile-generator.cc

Index: src/profile-generator.cc
diff --git a/src/profile-generator.cc b/src/profile-generator.cc
index b0c18e59fa8af10f9eb4f209604fe514a2047129..c4813a44c21cee13d6207ed74453beb05c619614 100644
--- a/src/profile-generator.cc
+++ b/src/profile-generator.cc
@@ -122,7 +122,7 @@ const char* StringsStorage::GetName(String* name) {
 }
 
 
-const char* CodeEntry::kEmptyNamePrefix = "";
+const char* const CodeEntry::kEmptyNamePrefix = "";
 
 
 void CodeEntry::CopyData(const CodeEntry& source) {
@@ -760,10 +760,12 @@ void SampleRateCalculator::UpdateMeasurements(double current_time) {
 }
 
 
-const char* ProfileGenerator::kAnonymousFunctionName = "(anonymous function)";
-const char* ProfileGenerator::kProgramEntryName = "(program)";
-const char* ProfileGenerator::kGarbageCollectorEntryName =
-  "(garbage collector)";
+const char* const ProfileGenerator::kAnonymousFunctionName =
+    "(anonymous function)";
+const char* const ProfileGenerator::kProgramEntryName =
+    "(program)";
+const char* const ProfileGenerator::kGarbageCollectorEntryName =
+    "(garbage collector)";
 
 
 ProfileGenerator::ProfileGenerator(CpuProfilesCollection* profiles)