Make debug mode work with new VS Code JS debugger (microsoft#39098)

Author: andrewbranch

src/compiler/sys.ts

@@ -1231,7 +1231,7 @@ namespace ts {
                 enableCPUProfiler,
                 disableCPUProfiler,
                 realpath,
-                debugMode: !!process.env.NODE_INSPECTOR_IPC || some(<string[]>process.execArgv, arg => /^--(inspect|debug)(-brk)?(=\d+)?$/i.test(arg)),
+                debugMode: !!process.env.NODE_INSPECTOR_IPC || !!process.env.VSCODE_INSPECTOR_OPTIONS || some(<string[]>process.execArgv, arg => /^--(inspect|debug)(-brk)?(=\d+)?$/i.test(arg)),
                 tryEnableSourceMapsForHost() {
                     try {
                         require("source-map-support").install();