Basic: Stop enabling NoncopyableGenerics, BorrowingSwitch, and MoveOnlyPartialConsumption.

These features are baseline features and therefore are considered to be
implicitly enabled. They don't need to be explicitly enabled or queried for in
any part of the compiler.

Author: tshortli

lib/Basic/LangOptions.cpp

@@ -51,11 +51,6 @@ LangOptions::LangOptions() {
   disableFeature(Feature::ExtensionMacros);
 #endif
 
-  // Note: Introduce default-on language options here.
-  enableFeature(Feature::NoncopyableGenerics);
-  enableFeature(Feature::BorrowingSwitch);
-  enableFeature(Feature::MoveOnlyPartialConsumption);
-
   // Enable any playground options that are enabled by default.
 #define PLAYGROUND_OPTION(OptionName, Description, DefaultOn, HighPerfOn) \
   if (DefaultOn) \

lib/SILOptimizer/Mandatory/MoveOnlyDiagnostics.cpp

@@ -828,10 +828,6 @@ void DiagnosticEmitter::emitCannotPartiallyMutateError(
     return;
   }
   case PartialMutationError::Kind::HasDeinit: {
-    assert(
-        astContext.LangOpts.hasFeature(Feature::MoveOnlyPartialConsumption) ||
-        astContext.LangOpts.hasFeature(
-            Feature::MoveOnlyPartialReinitialization));
     auto diagnostic = [&]() {
       switch (kind) {
       case PartialMutation::Kind::Consume:
@@ -851,10 +847,6 @@ void DiagnosticEmitter::emitCannotPartiallyMutateError(
     return;
   }
   case PartialMutationError::Kind::NonfrozenImportedType: {
-    assert(
-        astContext.LangOpts.hasFeature(Feature::MoveOnlyPartialConsumption) ||
-        astContext.LangOpts.hasFeature(
-            Feature::MoveOnlyPartialReinitialization));
     auto &nominal = error.getNonfrozenImportedNominal();
     auto diagnostic = [&]() {
       switch (kind) {
@@ -870,10 +862,6 @@ void DiagnosticEmitter::emitCannotPartiallyMutateError(
     return;
   }
   case PartialMutationError::Kind::NonfrozenUsableFromInlineType: {
-    assert(
-        astContext.LangOpts.hasFeature(Feature::MoveOnlyPartialConsumption) ||
-        astContext.LangOpts.hasFeature(
-            Feature::MoveOnlyPartialReinitialization));
     auto &nominal = error.getNonfrozenUsableFromInlineNominal();
     auto diagnostic = [&]() {
       switch (kind) {