Swift SIL: fix SIL.Type.builtinVectorElementType

The element type must be lowered. Otherwise it would crash for e.g. function types as element types.

Author: eeckstein

SwiftCompilerSources/Sources/Optimizer/Utilities/OptUtils.swift

@@ -387,7 +387,7 @@ extension Instruction {
     case let bi as BuiltinInst:
       switch bi.id {
       case .ZeroInitializer:
-        let type = bi.type.isBuiltinVector ? bi.type.builtinVectorElementType : bi.type
+        let type = bi.type.isBuiltinVector ? bi.type.builtinVectorElementType(in: parentFunction) : bi.type
         return type.isBuiltinInteger || type.isBuiltinFloat
       case .PtrToInt:
         return bi.operands[0].value is StringLiteralInst

SwiftCompilerSources/Sources/SIL/Type.swift

@@ -80,7 +80,9 @@ public struct Type : TypeProperties, CustomStringConvertible, NoReflectionChildr
     !isNoEscapeFunction && isEscapable(in: function)
   }
 
-  public var builtinVectorElementType: Type { canonicalType.builtinVectorElementType.silType! }
+  public func builtinVectorElementType(in function: Function) -> Type {
+    canonicalType.builtinVectorElementType.loweredType(in: function)
+  }
 
   public func builtinFixedArrayElementType(in function: Function, maximallyAbstracted: Bool = false) -> Type {
     canonicalType.builtinFixedArrayElementType.loweredType(in: function, maximallyAbstracted: maximallyAbstracted)