AST: Promote BuiltinAllocVector feature to baseline.

Author: tshortli

include/swift/Basic/Features.def

@@ -158,7 +158,7 @@ BASELINE_LANGUAGE_FEATURE(BuiltinCreateAsyncTaskWithExecutor, 0, "Task create bu
 BASELINE_LANGUAGE_FEATURE(BuiltinCreateAsyncDiscardingTaskInGroupWithExecutor, 0, "Task create in discarding task group with extra executor preference")
 BASELINE_LANGUAGE_FEATURE(BuiltinStackAlloc, 0, "Builtin.stackAlloc")
 BASELINE_LANGUAGE_FEATURE(BuiltinUnprotectedStackAlloc, 0, "Builtin.unprotectedStackAlloc")
-LANGUAGE_FEATURE(BuiltinAllocVector, 0, "Builtin.allocVector")
+BASELINE_LANGUAGE_FEATURE(BuiltinAllocVector, 0, "Builtin.allocVector")
 BASELINE_LANGUAGE_FEATURE(BuiltinTaskRunInline, 0, "Builtin.taskRunInline")
 BASELINE_LANGUAGE_FEATURE(BuiltinUnprotectedAddressOf, 0, "Builtin.unprotectedAddressOf")
 LANGUAGE_FEATURE(NewCxxMethodSafetyHeuristics, 0, "Only import C++ methods that return pointers (projections) on owned types as unsafe")

lib/AST/FeatureSet.cpp

@@ -124,8 +124,6 @@ static bool usesFeatureRethrowsProtocol(Decl *decl) {
   return usesFeatureRethrowsProtocol(decl, checked);
 }
 
-UNINTERESTING_FEATURE(BuiltinAllocVector)
-
 static bool usesFeatureNewCxxMethodSafetyHeuristics(Decl *decl) {
   return decl->hasClangNode();
 }

stdlib/public/core/Builtin.swift

@@ -1102,9 +1102,5 @@ func _getGlobalStringTablePointer(_ constant: String) -> UnsafePointer<CChar> {
 @_alwaysEmitIntoClient
 public
 func _allocateVector<Element>(elementType: Element.Type, capacity: Int) -> UnsafeMutablePointer<Element> {
-#if $BuiltinAllocVector
   return UnsafeMutablePointer(Builtin.allocVector(elementType, capacity._builtinWordValue))
-#else
-  fatalError("unsupported compiler")
-#endif
 }