misc/vim: add error type.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5331046

misc/vim/syntax/go.vim

@@ -18,7 +18,7 @@
 "     Highlights white space around the communications operator that don't follow
 "     the standard style.
 "   - go_highlight_extra_types
-"     Highlights commonly used library types (os.Error, etc.).
+"     Highlights commonly used library types (io.Reader, etc.).
 "   - go_highlight_space_tab_error
 "     Highlights instances of tabs following spaces.
 "   - go_highlight_trailing_whitespace_error
@@ -67,7 +67,7 @@ hi def link     goLabel             Label
 hi def link     goRepeat            Repeat
 
 " Predefined types
-syn keyword     goType              chan map bool string
+syn keyword     goType              chan map bool string error
 syn keyword     goSignedInts        int int8 int16 int32 int64 rune
 syn keyword     goUnsignedInts      byte uint uint8 uint16 uint32 uint64 uintptr
 syn keyword     goFloats            float32 float64
@@ -180,7 +180,6 @@ endif
 if go_highlight_extra_types != 0
   syn match goExtraType /\<bytes\.\(Buffer\)\>/
   syn match goExtraType /\<io\.\(Reader\|Writer\|ReadWriter\|ReadWriteCloser\)\>/
-  syn match goExtraType /\<\(os\.Error\)\>/
   syn match goExtraType /\<reflect\.\(Kind\|Type\|Value\)\>/
   syn match goExtraType /\<unsafe\.Pointer\>/
 endif