Do not look for existing shared function info when compiling a new script.

src/compiler.h

Index: src/compiler.h
diff --git a/src/compiler.h b/src/compiler.h
index a1f97df269c053951b279d691c1c03af74ae846d..cbcfec6a9f35cff263464a93f70adb12bf40c954 100644
--- a/src/compiler.h
+++ b/src/compiler.h
@@ -127,7 +127,8 @@ class CompilationInfo {
     kSplittingEnabled = 1 << 13,
     kTypeFeedbackEnabled = 1 << 14,
     kDeoptimizationEnabled = 1 << 15,
-    kSourcePositionsEnabled = 1 << 16
+    kSourcePositionsEnabled = 1 << 16,
+    kNewScript = 1 << 17,
   };
 
   explicit CompilationInfo(ParseInfo* parse_info);
@@ -245,6 +246,10 @@ class CompilationInfo {
 
   bool is_splitting_enabled() const { return GetFlag(kSplittingEnabled); }
 
+  void MarkAsNewScript() { SetFlag(kNewScript); }
+
+  bool is_new_script() const { return GetFlag(kNewScript); }
+
   bool IsCodePreAgingActive() const {
     return FLAG_optimize_for_size && FLAG_age_code && !will_serialize() &&
            !is_debug();