Tests: More test coverage in objc_async_conformance.swift

Add regression tests for rdar://125945942.

Author: tshortli

test/ClangImporter/objc_async_conformance.swift

@@ -135,3 +135,14 @@ class ImplementsDictionaryLoader3: DictionaryLoader {
 class ImplementsDictionaryLoader4: DictionaryLoader {
   func loadDictionary(completionHandler: @escaping ([String: Int]?) -> Void) {} // expected-note {{candidate has non-matching type '(@escaping ([String : Int]?) -> Void) -> ()'}}
 }
+
+class ImplementsFloatLoader: FloatLoader {
+  public func loadFloat(completionHandler: @escaping (Float) -> Void) {}
+}
+
+class ImplementsFloatLoader2: FloatLoader {
+  public func loadFloat(withCompletionHandler completionHandler: @escaping (Float) -> Void) {}
+  // expected-warning@-1 {{instance method 'loadFloat(withCompletionHandler:)' nearly matches optional requirement 'loadFloat(completionHandler:)' of protocol 'FloatLoader'}}
+  // expected-note@-2 {{rename to 'loadFloat(completionHandler:)' to satisfy this requirement}}
+  // expected-note@-3 {{move 'loadFloat(withCompletionHandler:)' to an extension to silence this warning}}
+}

test/Inputs/clang-importer-sdk/usr/include/ObjCConcurrency.h

@@ -359,4 +359,9 @@ MAIN_ACTOR
 - (void)loadDictionaryWithCompletionHandler:(void (^)(NSDictionary <NSString *, NSNumber *> * _Nullable))completionHandler;
 @end
 
+@protocol FloatLoader
+@optional
+- (void)loadFloatWithCompletionHandler:(void (^)(float))completionHandler;
+@end
+
 #pragma clang assume_nonnull end