Enable parser state cache by default

Only enables the parser state cache config option by default.

We don't actually generate the parser state cache when parsing normally, only when user explicitly calls `JsSerializeParserState`. The state object returned then needs to be passed back into either `JsRunScriptWithParserState` or `JsDeserializeParserState`.

The point of enabling this config option by default is so that user code doesn't hit an assert when trying to call those above 3 API.

Author: boingoing

lib/Common/ConfigFlagsList.h

@@ -451,7 +451,7 @@ PHASE(All)
 #define DEFAULT_CONFIG_HybridFgJit          (false)
 #define DEFAULT_CONFIG_HybridFgJitBgQueueLengthThreshold (32)
 #define DEFAULT_CONFIG_Prejit               (false)
-#define DEFAULT_CONFIG_ParserStateCache     (false)
+#define DEFAULT_CONFIG_ParserStateCache     (true)
 #define DEFAULT_CONFIG_CompressParserStateCache (false)
 #define DEFAULT_CONFIG_DeferTopLevelTillFirstCall (true)
 #define DEFAULT_CONFIG_DirectCallTelemetryStats (false)