Add support for fetching file path in fern file browser for asyncrun plugin

Author: skywind3000

autoload/asyncrun/locator.vim

@@ -119,6 +119,14 @@ function! asyncrun#locator#nofile_buffer_path() abort
 				catch
 				endtry
 			endif
+		elseif &ft == 'fern'
+			let t = bufname('%')
+			if t =~ '\v^fern\:\/\/\w+\/file\:\/\/'
+				let t = matchstr(t, '\v^fern\:\/\/\w+\/file\:\/\/\zs.*\ze\$')
+				if t != ''
+					return (s:windows)? strpart(t, 1) : t
+				endif
+			endif
 		endif
 		if exists('b:git_dir')
 			return b:git_dir