Allow to extract function literal

Author: zolotov

src/com/goide/inspections/GoInspectionUtil.java

@@ -31,7 +31,7 @@ private GoInspectionUtil() {}
   public static int getExpressionResultCount(GoExpression call) {
     if (call instanceof GoLiteral || call instanceof GoStringLiteral || call instanceof GoBinaryExpr ||
         call instanceof GoUnaryExpr && ((GoUnaryExpr)call).getSendChannel() == null || call instanceof GoBuiltinCallExpr ||
-        call instanceof GoCompositeLit || call instanceof GoIndexOrSliceExpr) {
+        call instanceof GoCompositeLit || call instanceof GoIndexOrSliceExpr || call instanceof GoFunctionLit) {
       return 1;
     }
     if (call instanceof GoParenthesesExpr) {

testData/refactor/introduce-variable/extractFunctionLiteral-after.go

@@ -0,0 +1,5 @@
+package a
+
+func a(s string) {
+	i := func(int, int) {}
+}

testData/refactor/introduce-variable/extractFunctionLiteral.go

@@ -0,0 +1,5 @@
+package a
+
+func a(s string) {
+	fun<caret>c(int, int) {}
+}

tests/com/goide/refactor/GoIntroduceVariableTest.java

@@ -60,6 +60,7 @@ private void doFailureTest(String msg) {
   public void testDoNotSuggestKeywordBasedOnType()                  { doTest(); }
   public void testDoNotSuggestKeywordBasedOnCallName()              { doTest(); }
   public void testDoNotSuggestNameEqualsToType()                    { doTest(); }
+  public void testExtractFunctionLiteral()                          { doTest(); }
 
   public void testExtractSingleExpressionStatement_1()              { doTest(); }
   public void testExtractSingleExpressionStatement_2()              { doTest(); }