AST: Promote BorrowingSwitch feature to baseline.

Author: tshortli

include/swift/Basic/Features.def

@@ -199,7 +199,7 @@ SUPPRESSIBLE_LANGUAGE_FEATURE(ConformanceSuppression, 426, "Suppressible inferre
 SUPPRESSIBLE_LANGUAGE_FEATURE(BitwiseCopyable2, 426, "BitwiseCopyable feature")
 LANGUAGE_FEATURE(BodyMacros, 415, "Function body macros")
 SUPPRESSIBLE_LANGUAGE_FEATURE(SendingArgsAndResults, 430, "Sending arg and results")
-LANGUAGE_FEATURE(BorrowingSwitch, 432, "Noncopyable type pattern matching")
+BASELINE_LANGUAGE_FEATURE(BorrowingSwitch, 432, "Noncopyable type pattern matching")
 CONDITIONALLY_SUPPRESSIBLE_LANGUAGE_FEATURE(IsolatedAny, 431, "@isolated(any) function types")
 LANGUAGE_FEATURE(IsolatedAny2, 431, "@isolated(any) function types")
 LANGUAGE_FEATURE(ObjCImplementation, 436, "@objc @implementation extensions")

lib/AST/FeatureSet.cpp

@@ -422,8 +422,6 @@ UNINTERESTING_FEATURE(DynamicActorIsolation)
 
 UNINTERESTING_FEATURE(NonfrozenEnumExhaustivity)
 
-UNINTERESTING_FEATURE(BorrowingSwitch)
-
 UNINTERESTING_FEATURE(ClosureIsolation)
 
 static bool usesFeatureConformanceSuppression(Decl *decl) {