Don't treat missing imports as an error when -debugger-support is on.

For now, also check that -playground is off; once <rdar://problem/18090611>
is in we can drop this check and treat them as mostly orthogonal options.

Part of <rdar://problem/17994094>

Swift SVN r21385

lib/Sema/NameBinding.cpp

@@ -142,8 +142,10 @@ NameBinder::addImport(SmallVectorImpl<std::pair<ImportedModule, bool>> &imports,
                [&] { modulePathStr += "."; });
 
     auto diagKind = diag::sema_no_import;
-    if (SF.Kind == SourceFileKind::REPL)
+    if (SF.Kind == SourceFileKind::REPL ||
+        (Context.LangOpts.DebuggerSupport && !Context.LangOpts.Playground)) {
       diagKind = diag::sema_no_import_repl;
+    }
     diagnose(ID->getLoc(), diagKind, modulePathStr);
 
     if (Context.SearchPathOpts.SDKPath.empty()) {

test/Parse/debugger.swift

@@ -1,6 +1,10 @@
 // RUN: %swift %s -verify -debugger-support
 
+import Nonexistent_Module // expected-error {{no such module}}
+
 var ($x0, $x1) = (4, 3)
 var z = $x0 + $x1
 
 z // no error.
+
+var x: Double = z // expected-error {{'Int' is not convertible to 'Double'}}

test/PlaygroundTransform/declarations_error.swift

@@ -1,4 +1,9 @@
 // RUN: rm -rf %t && mkdir %t
 // RUN: cp %s %t/main.swift
-// RUN: %swift -parse -playground %t/main.swift -verify
-var $a = 2 // expected-error {{expected numeric value following '$'}}
+// RUN: not %swift -parse -playground %t/main.swift 2>&1 | FileCheck %s
+// RUN: not %swift -parse -playground -debugger-support %t/main.swift 2>&1 | FileCheck %s
+
+// CHECK: error: no such module
+import Nonexistent_Module
+// CHECK-NOT: error
+import Another_Nonexistent_Module

test/PlaygroundTransform/import_error.swift

@@ -0,0 +1,4 @@
+// RUN: rm -rf %t && mkdir %t
+// RUN: cp %s %t/main.swift
+// RUN: %swift -parse -playground %t/main.swift -verify
+var $a = 2 // expected-error {{expected numeric value following '$'}}