[Diagnostics] Re-phrase note about inferred async effect from an operation in a closure body

Author: xedin

include/swift/AST/DiagnosticsSema.def

@@ -563,8 +563,8 @@ ERROR(cannot_pass_async_func_to_sync_parameter,none,
       "cannot pass function of type %0 "
       "to parameter expecting synchronous function type", (Type))
 
-NOTE(async_in_closure_that_does_not_support_concurrency,none,
-     "'async' in a closure that does not support concurrency", ())
+NOTE(async_inferred_from_operation,none,
+     "'async' inferred from asynchronous operation used here", ())
 
 // Key-path expressions.
 ERROR(expr_keypath_no_objc_runtime,none,

lib/Sema/CSDiagnostics.cpp

@@ -5896,9 +5896,8 @@ bool AsyncFunctionConversionFailure::diagnoseAsError() {
       // 'async' effect is inferred from the body of the closure.
       if (asyncLoc.isInvalid()) {
         if (auto asyncNode = findAsyncNode(closure)) {
-          emitDiagnosticAt(
-              ::getLoc(asyncNode),
-              diag::async_in_closure_that_does_not_support_concurrency);
+          emitDiagnosticAt(::getLoc(asyncNode),
+                           diag::async_inferred_from_operation);
         }
       }
     }

test/Concurrency/async_sequence_syntax.swift

@@ -35,7 +35,7 @@ func missingTryInBlock<T : AsyncSequence>(_ seq: T) {
 func missingAsyncInBlock<T : AsyncSequence>(_ seq: T) { 
   execute { // expected-error{{cannot pass function of type '() async -> Void' to parameter expecting synchronous function type}}
     do { 
-      for try await _ in seq { } // expected-note {{'async' in a closure that does not support concurrency}}
+      for try await _ in seq { } // expected-note {{'async' inferred from asynchronous operation used here}}
     } catch { }
   }
 }

test/Concurrency/async_tasks.swift

@@ -48,7 +48,7 @@ func test_unsafeContinuations() async {
   // the closure should not allow async operations;
   // after all: if you have async code, just call it directly, without the unsafe continuation
   let _: String = withUnsafeContinuation { continuation in // expected-error{{cannot pass function of type '(UnsafeContinuation<String, Never>) async -> Void' to parameter expecting synchronous function type}}
-    let s = await someAsyncFunc() // expected-note {{'async' in a closure that does not support concurrency}}
+    let s = await someAsyncFunc() // expected-note {{'async' inferred from asynchronous operation used here}}
     continuation.resume(returning: s)
   }