Add support for copying files and folders.

vendor/github.com/evanw/esbuild/internal/api_helpers/use_timer.go

@@ -0,0 +1,7 @@
+package api_helpers
+
+// This flag is set by the CLI to activate the timer. It's put here instead of
+// by the timer to discourage code from checking this flag. Only the code that
+// creates the root timer should check this flag. Other code should check that
+// the timer is not null to detect if the timer is being used or not.
+var UseTimer bool