[move-only-address] When emitting a simple assignment, make sure to consume the move only type.

This was an oversight since I thought that `let _ = x` and `_ = x` were
codegened in the same way.

rdar://102491017

Author: gottesmm

lib/SILGen/SILGenExpr.cpp

@@ -4758,7 +4758,19 @@ static void emitSimpleAssignment(SILGenFunction &SGF, SILLocation loc,
         FormalEvaluationScope writeback(SGF);
         auto srcLV = SGF.emitLValue(srcLoad->getSubExpr(),
                                     SGFAccessKind::IgnoredRead);
-        (void) SGF.emitLoadOfLValue(loc, std::move(srcLV), SGFContext());
+        RValue rv = SGF.emitLoadOfLValue(loc, std::move(srcLV), SGFContext());
+        // If we have a move only type, we need to implode and perform a move to
+        // ensure we consume our argument as part of the assignment. Otherwise,
+        // we don't do anything.
+        if (rv.getLoweredType(SGF).isMoveOnly()) {
+          ManagedValue value = std::move(rv).getAsSingleValue(SGF, loc);
+          // If we have an address, then ensure plus one will create a temporary
+          // copy which will act as a consume of the address value. If we have
+          // an object, we need to insert our own move though.
+          value = value.ensurePlusOne(SGF, loc);
+          if (value.getType().isObject())
+            value = SGF.B.createMoveValue(loc, value);
+        }
         return;
       }
 

test/SILOptimizer/moveonly_addresschecker_diagnostics.swift

@@ -2067,24 +2067,41 @@ public func closureAndClosureCaptureClassArgUseAfterConsume(_ x2: inout Klass) {
 /////////////////////////////
 
 func moveOperatorTest(_ k: __owned Klass) {
-    var k2 = k // expected-error {{'k2' consumed more than once}}
+    var k2 = k
+    // expected-error @-1 {{'k2' consumed more than once}}
+    // expected-error @-2 {{'k2' consumed more than once}}
+    // expected-error @-3 {{'k2' consumed more than once}}
     k2 = Klass()
     let k3 = _move k2 // expected-note {{consuming use}}
     let _ = _move k2 // expected-note {{consuming use}}
+    _ = k2 // expected-note {{consuming use}}
+    let _ = k2
+    // expected-note @-1 {{consuming use}}
+    // expected-note @-2 {{consuming use}}
+    // expected-note @-3 {{consuming use}}
     let _ = k3
 }
 
 /////////////////////////////////////////
 // Black hole initialization test case//
 /////////////////////////////////////////
 
-func blackHoleTestCase(_ k: __owned Klass) {
-    var k2 = k // expected-error {{'k2' consumed more than once}}
+func blackHoleKlassTestCase(_ k: __owned Klass) {
+    var k2 = k
     // expected-error @-1 {{'k2' consumed more than once}}
+    // expected-error @-2 {{'k2' consumed more than once}}
+    // expected-error @-3 {{'k2' consumed more than once}}
+    // expected-error @-4 {{'k2' consumed more than once}}
     let _ = k2 // expected-note {{consuming use}}
     let _ = k2 // expected-note {{consuming use}}
 
     k2 = Klass()
     var _ = k2 // expected-note {{consuming use}}
     var _ = k2 // expected-note {{consuming use}}
+
+    _ = k2 // expected-note {{consuming use}}
+    _ = k2
+    // expected-note @-1 {{consuming use}}
+    // expected-note @-2 {{consuming use}}
+    // expected-note @-3 {{consuming use}}
 }

test/SILOptimizer/moveonly_deinits.swift

@@ -12,11 +12,14 @@ struct MoveOnlyStruct {
     deinit { // expected-error {{'self' consumed more than once}}
         let x = self // expected-note {{consuming use}}
         _ = x
-        var y = MoveOnlyStruct()
+        var y = MoveOnlyStruct() // expected-error {{'y' consumed more than once}}
         y = self // expected-note {{consuming use}}
         // We get an infinite recursion since we are going to call our own
         // deinit here. We are just testing diagnostics here though.
         _ = y // expected-warning {{function call causes an infinite recursion}}
+        // expected-note @-1 {{consuming use}}
+        let z = y // expected-note {{consuming use}}
+        let _ = z
         globalMoveOnlyStruct = self // expected-note {{consuming use}}
     } // expected-note {{consuming use}}
 }