[CodeCompletion] Don't complete .members after a space

This lets us filter down to binary operators, etc.

rdar://problem/25994246

Author: benlangmuir

lib/IDE/CodeCompletion.cpp

@@ -2654,6 +2654,9 @@ class CompletionLookup final : public swift::VisibleDeclConsumer {
       if (HaveLParen)
         return;
 
+      if (HaveLeadingSpace && !HaveDot)
+        return;
+
       if (auto *VD = dyn_cast<VarDecl>(D)) {
         addVarDeclRef(VD, Reason);
         return;

test/IDE/complete_value_expr.swift

@@ -170,6 +170,8 @@
 // RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=GENERIC_TYPEALIAS_1 | FileCheck %s -check-prefix=GENERIC_TYPEALIAS_1
 // RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=GENERIC_TYPEALIAS_2 | FileCheck %s -check-prefix=GENERIC_TYPEALIAS_2
 
+// RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=AFTER_SPACE_1 | FileCheck %s -check-prefix=AFTER_SPACE_1
+
 // Test code completion of expressions that produce a value.
 
 struct FooStruct {
@@ -1882,3 +1884,8 @@ func testGenericTypealias2() {
   Enclose.#^GENERIC_TYPEALIAS_2^#
 }
 // GENERIC_TYPEALIAS_2: Decl[TypeAlias]/CurrNominal:        MyPair[#(T, T)#];
+
+func testAfterSpace(x: Int?) {
+  x #^AFTER_SPACE_1^#
+// AFTER_SPACE_1-NOT: CurrNominal
+}

test/SourceKit/CodeComplete/complete_operators.swift

@@ -5,6 +5,7 @@
 // RUN: %complete-test -tok=OPT_OPERATORS %s | FileCheck %s -check-prefix=OPT
 // RUN: %complete-test -tok=KNOWN_OPERATORS_1 %s | FileCheck %s -check-prefix=KNOWN
 // RUN: %complete-test -tok=KNOWN_OPERATORS_2 %s | FileCheck %s -check-prefix=KNOWN
+// RUN: %complete-test -tok=NO_DOT %s | FileCheck %s -check-prefix=NO_DOT
 
 struct MyInt {
   var bigPowers: Int { return 1 }
@@ -167,3 +168,11 @@ func test6(x: DoesEverything) {
 // KNOWN: ===
 // KNOWN: !==
 // KNOWN: ~=
+
+func test7() {
+  var x: DoesEverything
+  x #^NO_DOT^#
+}
+// NO_DOT-NOT: .
+// NO_DOT: =
+// NO_DOT: ==