[CSFix] Make it possible to diagnose calls to non-functions in ambiguity contexts

Resolves: rdar://86611718
(cherry picked from commit d5b11a6)

Author: xedin

include/swift/Sema/CSFix.h

@@ -2235,6 +2235,10 @@ class RemoveInvalidCall final : public ConstraintFix {
 
   bool diagnose(const Solution &solution, bool asNote = false) const override;
 
+  bool diagnoseForAmbiguity(CommonFixesArray commonFixes) const override {
+    return diagnose(*commonFixes.front().first);
+  }
+
   static RemoveInvalidCall *create(ConstraintSystem &cs,
                                    ConstraintLocator *locator);
 

test/Constraints/diagnostics.swift

@@ -1484,3 +1484,8 @@ func testUnwrapFixIts(x: Int?) throws {
   // expected-note@-2 {{force-unwrap using '!' to abort execution if the optional value contains 'nil'}} {{42-42=!}}
   let _: Int = try! .optionalThrowsMember ?? 0
 }
+
+func rdar86611718(list: [Int]) {
+  String(list.count())
+  // expected-error@-1 {{cannot call value of non-function type 'Int'}}
+}

test/type/protocol_composition.swift

@@ -177,7 +177,7 @@ takesP1AndP2([Swift.DoesNotExist & P1 & P2]()) // expected-error {{module 'Swift
 // expected-error@-1 {{binary operator '&' cannot be applied to operands of type 'UInt8' and 'P1.Protocol'}}
 // expected-error@-2 {{binary operator '&' cannot be applied to operands of type 'UInt8' and 'P2.Protocol'}}
 // expected-note@-3 2 {{overloads for '&' exist with these partially matching parameter lists}}
-
+// expected-error@-4 {{cannot call value of non-function type '[UInt8]'}}
 
 typealias T08 = P1 & inout P2 // expected-error {{'inout' may only be used on parameters}}
 typealias T09 = P1 & __shared P2 // expected-error {{'__shared' may only be used on parameters}}