[AddressLowering] Handle existential_metatype.

The handling is the same as for value_metatype.

Author: nate-chandler

lib/SILOptimizer/Mandatory/AddressLowering.cpp

@@ -2618,6 +2618,11 @@ class UseRewriter : SILInstructionVisitor<UseRewriter> {
     vmi->setOperand(opAddr);
   }
 
+  void visitExistentialMetatypeInst(ExistentialMetatypeInst *emi) {
+    SILValue opAddr = addrMat.materializeAddress(use->get());
+    emi->setOperand(opAddr);
+  }
+
   void visitAddressOfBorrowBuiltinInst(BuiltinInst *bi, bool stackProtected) {
     SILValue value = bi->getOperand(0);
     SILValue addr = pass.valueStorageMap.getStorage(value).storageAddress;

test/SILOptimizer/opaque_values_Onone_stdlib.swift

@@ -1,10 +1,32 @@
-// RUN: %target-swift-frontend -parse-stdlib -enable-experimental-move-only -module-name main -enable-sil-opaque-values -parse-as-library -emit-sil -Onone %s | %FileCheck %s
+// RUN: %target-swift-frontend -parse-stdlib -enable-experimental-move-only -module-name Swift -enable-sil-opaque-values -parse-as-library -emit-sil -Onone %s | %FileCheck %s
 
 // Like opaque_values_Onone.swift but for code that needs to be compiled with 
 // -parse-stdlib.
 
-class X {}
+precedencegroup AssignmentPrecedence { assignment: true }
+precedencegroup CastingPrecedence {}
+
+public protocol _ObjectiveCBridgeable {}
+
+public protocol _ExpressibleByBuiltinBooleanLiteral {
+  init(_builtinBooleanLiteral value: Builtin.Int1)
+}
+struct Bool : _ExpressibleByBuiltinBooleanLiteral {
+  var _value: Builtin.Int1
+  @_silgen_name("Bool_init_noargs")
+  init()
+  init(_ v: Builtin.Int1) { self._value = v }
+  init(_ value: Bool) { self = value }
+  init(_builtinBooleanLiteral value: Builtin.Int1) {
+    self._value = value
+  }
+}
 
+@_silgen_name("typeof")
+@_semantics("typechecker.type(of:)")
+public func type<T, Metatype>(of value: T) -> Metatype
+
+class X {}
 func consume(_ x : __owned X) {}
 
 func foo(@_noImplicitCopy _ x: __owned X) {
@@ -70,3 +92,8 @@ func toObject<T>(_ object: inout T) -> Builtin.BridgeObject {
 func getAnotherType<T, U>(_ object: inout T, to ty: U.Type) -> U {
   Builtin.reinterpretCast(object)
 }
+
+@_silgen_name("isOfTypeOfAnyObjectType")
+func isOfTypeOfAnyObjectType(fromAny any: Any) -> Bool {
+  type(of: any) is Builtin.AnyObject.Type
+}