[NoncopyableGenerics] fix parallel assignments

Author: kavon

lib/AST/Type.cpp

@@ -205,7 +205,8 @@ bool TypeBase::isNoncopyable(const DeclContext *dc) {
 
 /// \returns true iff this type lacks conformance to Copyable.
 bool TypeBase::isNoncopyable() {
-  auto canType = getCanonicalType();
+  // Strip @lvalue and canonicalize.
+  auto canType = getRValueType()->getCanonicalType();
   auto &ctx = canType->getASTContext();
 
   // for legacy-mode queries that are not dependent on conformances to Copyable

test/ModuleInterface/Inputs/NoncopyableGenerics.swift

@@ -8,3 +8,16 @@ public struct Vector<T: ~Copyable> {
     fatalError("todo")
   }
 }
+
+
+
+
+// These are purely to add test coverage of different constructs
+public struct Toys {
+  static func test_parallelAssignment() {
+    var y: Int
+    var x: Int
+    (x, y) = (10, 11)
+  }
+
+}