Issue #27713: Surpress spurious build warnings when updating importlib's

bootstrap files:
    Could not find platform dependent libraries <exec_prefix
    Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Patch by Xiang Zhang

Misc/NEWS

@@ -177,6 +177,9 @@ Windows
 Build
 -----
 
+- Issue #27713: Surpress spurious build warnings when updating importlib's
+  bootstrap files.  Patch by Xiang Zhang
+
 - Issue #25825: Correct the references to Modules/python.exp, which is
   required on AIX.  The references were accidentally changed in 3.5.0a1.
 

Programs/_freeze_importlib.c

@@ -77,6 +77,7 @@ main(int argc, char *argv[])
     Py_NoUserSiteDirectory++;
     Py_NoSiteFlag++;
     Py_IgnoreEnvironmentFlag++;
+    Py_FrozenFlag++;
 
     Py_SetProgramName(L"./_freeze_importlib");
     /* Don't install importlib, since it could execute outdated bytecode. */