Moved all packages in core, base, vendor, tests and examples to use new #+ file tag syntax.

core/fmt/example.odin

@@ -1,4 +1,4 @@
-//+build ignore
+#+build ignore
 package custom_formatter_example
 import "core:fmt"
 import "core:io"

core/fmt/fmt_js.odin

@@ -1,4 +1,4 @@
-//+build js
+#+build js
 package fmt
 
 import "core:bufio"

core/fmt/fmt_os.odin

@@ -1,6 +1,6 @@
-//+build !freestanding
-//+build !js
-//+build !orca
+#+build !freestanding
+#+build !js
+#+build !orca
 package fmt
 
 import "base:runtime"