Add syntax files from upstream vim repository

compiler/gcc.vim

@@ -0,0 +1,45 @@
+if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'vim') == -1
+  
+" Vim compiler file
+" Compiler:             GNU C Compiler
+" Previous Maintainer:  Nikolai Weibull <now@bitwi.se>
+" Latest Revision:      2010-10-14
+" 			added line suggested by Anton Lindqvist 2016 Mar 31
+
+if exists("current_compiler")
+  finish
+endif
+let current_compiler = "gcc"
+
+let s:cpo_save = &cpo
+set cpo&vim
+
+CompilerSet errorformat=
+      \%*[^\"]\"%f\"%*\\D%l:%c:\ %m,
+      \%*[^\"]\"%f\"%*\\D%l:\ %m,
+      \\"%f\"%*\\D%l:%c:\ %m,
+      \\"%f\"%*\\D%l:\ %m,
+      \%-G%f:%l:\ %trror:\ (Each\ undeclared\ identifier\ is\ reported\ only\ once,
+      \%-G%f:%l:\ %trror:\ for\ each\ function\ it\ appears\ in.),
+      \%f:%l:%c:\ %trror:\ %m,
+      \%f:%l:%c:\ %tarning:\ %m,
+      \%f:%l:%c:\ %m,
+      \%f:%l:\ %trror:\ %m,
+      \%f:%l:\ %tarning:\ %m,
+      \%f:%l:\ %m,
+      \%f:\\(%*[^\\)]\\):\ %m,
+      \\"%f\"\\,\ line\ %l%*\\D%c%*[^\ ]\ %m,
+      \%D%*\\a[%*\\d]:\ Entering\ directory\ [`']%f',
+      \%X%*\\a[%*\\d]:\ Leaving\ directory\ [`']%f',
+      \%D%*\\a:\ Entering\ directory\ [`']%f',
+      \%X%*\\a:\ Leaving\ directory\ [`']%f',
+      \%DMaking\ %*\\a\ in\ %f
+
+if exists('g:compiler_gcc_ignore_unmatched_lines')
+  CompilerSet errorformat+=%-G%.%#
+endif
+
+let &cpo = s:cpo_save
+unlet s:cpo_save
+
+endif