Merge pull request #3580 from zhengbli/master

Fix the issue that the "out" path is not relative to the path of tsconfig.json

src/compiler/commandLineParser.ts

@@ -110,6 +110,7 @@ namespace ts {
         {
             name: "out",
             type: "string",
+            isFilePath: true,
             description: Diagnostics.Concatenate_and_emit_output_to_single_file,
             paramType: Diagnostics.FILE,
         },