Partially fixes microsoft#6982 (double comments in arrow fuction).

Author: Anton Tolmachev

src/compiler/emitter.ts

@@ -4558,6 +4558,7 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
                 const { kind, parent } = node;
                 if (kind !== SyntaxKind.MethodDeclaration &&
                     kind !== SyntaxKind.MethodSignature &&
+                    kind !== SyntaxKind.ArrowFunction &&
                     parent &&
                     parent.kind !== SyntaxKind.PropertyAssignment &&
                     parent.kind !== SyntaxKind.CallExpression &&

tests/baselines/reference/commentsBeforeFunctionExpression1.js

@@ -2,9 +2,13 @@
 var v = {
     f: /**own f*/ (a) => 0
 }
+var w = 
+/* 1 */ (a) => 0;
 
 
 //// [commentsBeforeFunctionExpression1.js]
 var v = {
     f: /**own f*/ function (a) { return 0; }
 };
+var w = 
+/* 1 */ function (a) { return 0; };

tests/baselines/reference/commentsBeforeFunctionExpression1.symbols

@@ -6,4 +6,9 @@ var v = {
 >f : Symbol(f, Decl(commentsBeforeFunctionExpression1.ts, 0, 9))
 >a : Symbol(a, Decl(commentsBeforeFunctionExpression1.ts, 1, 19))
 }
+var w = 
+>w : Symbol(w, Decl(commentsBeforeFunctionExpression1.ts, 3, 3))
+
+/* 1 */ (a) => 0;
+>a : Symbol(a, Decl(commentsBeforeFunctionExpression1.ts, 4, 9))
 

tests/baselines/reference/commentsBeforeFunctionExpression1.types

@@ -9,4 +9,11 @@ var v = {
 >a : any
 >0 : number
 }
+var w = 
+>w : (a: any) => number
+
+/* 1 */ (a) => 0;
+>(a) => 0 : (a: any) => number
+>a : any
+>0 : number
 

tests/cases/compiler/commentsBeforeFunctionExpression1.ts

@@ -1,4 +1,6 @@
-// @removeComments: false
-var v = {
-    f: /**own f*/ (a) => 0
-}
+// @removeComments: false
+var v = {
+    f: /**own f*/ (a) => 0
+}
+var w = 
+/* 1 */ (a) => 0;