[Compiler] Add Swift compiler (#142)

Set makeprg to `swiftc`.

compiler/swift.vim

@@ -0,0 +1,39 @@
+" Vim compiler file
+" Compiler:         Swift Compiler
+" Maintainer:       Ayman Bagabas <ayman.bagabas@gmail.com>
+" Latest Revision:  2020 Feb 16
+
+if exists("current_compiler")
+    finish
+endif
+let current_compiler = "swiftc"
+
+" vint: -ProhibitAbbreviationOption
+let s:save_cpo = &cpo
+set cpo&vim
+" vint: +ProhibitAbbreviationOption
+
+if exists(":CompilerSet") != 2
+    command -nargs=* CompilerSet setlocal <args>
+endif
+
+if has('patch-7.4.191')
+    CompilerSet makeprg=swiftc\ \%:S
+else
+    CompilerSet makeprg=swiftc\ \%
+endif
+
+CompilerSet errorformat=
+                \%E%f:%l:%c:\ %trror:\ %m,
+                \%W%f:%l:%c:\ %tarning:\ %m,
+                \%I%f:%l:%c:\ note:\ %m,
+                \%E%f:%l:\ %trror:\ %m,
+                \%W%f:%l:\ %tarning:\ %m,
+                \%I%f:%l:\ note:\ %m,
+
+" vint: -ProhibitAbbreviationOption
+let &cpo = s:save_cpo
+unlet s:save_cpo
+" vint: +ProhibitAbbreviationOption
+
+" vim: set et sw=4 sts=4 ts=8: