[1.10>master] [MERGE #5561 @dilijev] Revert overzealous failfast logic which tried to improve detection of i18n initialization issues

Merge pull request #5561 from dilijev:revert-charclass-failfast

See OS#10368428

See original PR #5375

Author: dilijev

lib/Parser/CharClassifier.cpp

@@ -411,7 +411,12 @@ Js::CharClassifier::CharClassifier(void)
     bool isES6UnicodeModeEnabled = CONFIG_FLAG(ES6Unicode);
     bool isFullUnicodeSupportAvailable = PlatformAgnostic::UnicodeText::IsExternalUnicodeLibraryAvailable();
 
-#if INTL_ICU || INTL_WINGLOB // don't assert in _no_icu builds (where there is no i18n library, by design)
+// The following assertions are intentionally excluded from ChakraCore by guarding on NTBUILD.
+// This is to work around limitations of the i18n library downlevel (Win7, Win 8.0)
+// where CharClassifier functionality is not available.
+// TODO: Ideally, we would use the following guard instead to assert when an i18n library is available:
+// #if INTL_ICU || INTL_WINGLOB
+#ifdef NTBUILD
     AssertMsg(isFullUnicodeSupportAvailable, "Windows.Globalization needs to present with IUnicodeCharacterStatics support for Chakra.dll to work");
     if (!isFullUnicodeSupportAvailable)
     {
@@ -450,6 +455,7 @@ Js::CharClassifier::CharClassifier(void)
         getBigCharFlagsFunc = &CharClassifier::GetBigCharFlagsES5;
     }
 #endif
+
 }
 
 const OLECHAR* Js::CharClassifier::SkipWhiteSpaceNonSurrogate(LPCOLESTR psz, const CharClassifier *instance)

lib/Runtime/PlatformAgnostic/Platform/Windows/UnicodeText.cpp

@@ -416,23 +416,9 @@ namespace PlatformAgnostic
                     {
                         return true;
                     }
-#if INTL_ICU || INTL_WINGLOB // don't assert in _no_icu builds (where there is no i18n library, by design)
-                    else
-                    {
-                        // did not find winGlobCharApi
-                        Js::Throw::FatalInternalGlobalizationError();
-                    }
-                }
-                else
-                {
-                    // failed to initialize Windows Globalization
-                    Js::Throw::FatalInternalGlobalizationError();
-#endif
                 }
 
-#if (INTL_ICU || INTL_WINGLOB) && !defined(DBG)
-                return false; // in debug builds, this is unreachable code
-#endif
+                return false;
             }, false);
         }
 #endif // HAS_ICU