[Completion] Don't complete call arguments after .

Completing call argument patterns here is invalid.

rdar://127760308

Author: hamishknight

lib/IDE/CodeCompletion.cpp

@@ -1484,7 +1484,8 @@ void CodeCompletionCallbacksImpl::postfixCompletion(SourceLoc CompletionLoc,
   // closure. In that case, also suggest labels for additional trailing
   // closures.
   if (auto AE = dyn_cast<ApplyExpr>(ParsedExpr)) {
-    if (AE->getArgs()->hasAnyTrailingClosures()) {
+    if (AE->getArgs()->hasAnyTrailingClosures() &&
+        Kind == CompletionKind::PostfixExpr) {
       ASTContext &Ctx = CurDeclContext->getASTContext();
 
       // Modify the call that has the code completion expression as an

test/IDE/complete_multiple_trailingclosure.swift

@@ -99,6 +99,17 @@ func testOptionalInit() {
 // INIT_OPTIONAL_NEWLINE-DAG: Decl[Struct]/CurrModule:            MyStruct[#MyStruct#]; name=MyStruct
 }
 
+func testOptionalInitDot() {
+  // When there's a dot, we don't complete for the closure argument.
+  TestStruct2 {
+    2
+  }
+  .#^INIT_OPTIONAL_DOT^#
+  // INIT_OPTIONAL_DOT:     Begin completions, 2 items
+  // INIT_OPTIONAL_DOT-DAG: Keyword[self]/CurrNominal:          self[#TestStruct2#]; name=self
+  // INIT_OPTIONAL_DOT-DAG: Decl[InstanceMethod]/CurrNominal:   testStructMethod()[#Void#]; name=testStructMethod()
+}
+
 struct TestStruct3 {
   init(fn1: () -> Int, fn2: () -> String, fn3: () -> String) {}
   func testStructMethod() {}