Optimizer: move DiagnoseStaticExclusivity after MandatoryAllocBoxToStack

This is needed because MandatoryAllocBoxToStack can convert dynamic accesses to static accesses.
Also, it improves diagnostics for closure captures.

Author: eeckstein

lib/SILOptimizer/PassManager/PassPipeline.cpp

@@ -117,7 +117,6 @@ static void addMandatoryDiagnosticOptPipeline(SILPassPipelinePlan &P) {
   P.startPipeline("Mandatory Diagnostic Passes + Enabling Optimization Passes");
   P.addDiagnoseInvalidEscapingCaptures();
   P.addReferenceBindingTransform();
-  P.addDiagnoseStaticExclusivity();
   P.addNestedSemanticFunctionCheck();
   P.addCapturePromotion();
 
@@ -130,6 +129,10 @@ static void addMandatoryDiagnosticOptPipeline(SILPassPipelinePlan &P) {
 #else
   P.addLegacyAllocBoxToStack();
 #endif
+  // Needs to run after MandatoryAllocBoxToStack, because MandatoryAllocBoxToStack
+  // can convert dynamic accesses to static accesses.
+  P.addDiagnoseStaticExclusivity();
+
   P.addNoReturnFolding();
   P.addBooleanLiteralFolding();
   addDefiniteInitialization(P);

test/SILGen/moveonly_escaping_closure.swift

@@ -143,7 +143,7 @@ func testLocalLetClosureCaptureVar() {
         consumeVal(x) // expected-note {{consumed here}}
         // expected-note @-1 {{consumed again here}}
         borrowConsumeVal(x, x)
-        // expected-error @-1 {{overlapping accesses, but deinitialization requires exclusive access}}
+        // expected-error @-1 {{overlapping accesses to 'x', but deinitialization requires exclusive access}}
         // expected-note @-2 {{conflicting access is here}}
         // expected-note @-3 {{used here}}
         // expected-note @-4 {{used here}}
@@ -975,7 +975,7 @@ func testLocalLetClosureCaptureConsuming(_ x: consuming SingleElt) {
         consumeVal(x) // expected-note {{consumed here}}
         // expected-note @-1 {{consumed again here}}
         borrowConsumeVal(x, x) // expected-note {{used here}}
-        // expected-error @-1 {{overlapping accesses, but deinitialization requires exclusive access}}
+        // expected-error @-1 {{overlapping accesses to 'x', but deinitialization requires exclusive access}}
         // expected-note @-2 {{conflicting access is here}}
         // expected-note @-3 {{consumed here}}
         // expected-note @-4 {{used here}}

test/SILOptimizer/exclusivity_static_diagnostics.swift

@@ -263,12 +263,9 @@ func callsClosureLiteralImmediately() {
 
 func callsStoredClosureLiteral() {
   var i = 7;
-  let c = { (p: inout Int) in i}
+  let c = { (p: inout Int) in i} // expected-note {{conflicting access is here}}
 
-  // Closure literals that are stored and later called are treated as escaping
-  // We don't expect a static exclusivity diagnostic here, but the issue
-  // will be caught at run time
-  _ = c(&i) // no-error
+  _ = c(&i) // expected-error {{overlapping accesses to 'i', but modification requires exclusive access; consider copying to a local variable}}
 }