Frontend: sanitize version numbers beyond the scope of llvm::VersionTuple

rdar://78160707

Author: nkcsgexi

lib/Frontend/ArgsToFrontendOptionsConverter.cpp

@@ -103,7 +103,11 @@ bool ArgsToFrontendOptionsConverter::convert(
   }
 
   if (auto A = Args.getLastArg(OPT_user_module_version)) {
-    if (Opts.UserModuleVersion.tryParse(StringRef(A->getValue()))) {
+    StringRef raw(A->getValue());
+    while(raw.count('.') > 3) {
+      raw = raw.rsplit('.').first;
+    }
+    if (Opts.UserModuleVersion.tryParse(raw)) {
       Diags.diagnose(SourceLoc(), diag::error_invalid_arg_value,
                      A->getAsString(Args), A->getValue());
     }

test/ModuleInterface/user-module-version.swift

@@ -3,7 +3,7 @@
 // RUN: %empty-directory(%t/binary)
 // RUN: %empty-directory(%t/module-cache)
 
-// RUN: %target-swift-frontend -emit-module %s -module-name Foo -swift-version 5 -disable-implicit-concurrency-module-import -user-module-version 113.33.44.55 -emit-module-interface-path %t/textual/Foo.swiftinterface -enable-library-evolution -emit-module-path %t/binary/Foo.swiftmodule
+// RUN: %target-swift-frontend -emit-module %s -module-name Foo -swift-version 5 -disable-implicit-concurrency-module-import -user-module-version 113.33.44.55.66.77 -emit-module-interface-path %t/textual/Foo.swiftinterface -enable-library-evolution -emit-module-path %t/binary/Foo.swiftmodule
 
 // RUN: %FileCheck %s --check-prefix=INTERFACE-FLAG < %t/textual/Foo.swiftinterface