Go and govet checkers: make go executable configurable.

syntax_checkers/go/go.vim

@@ -23,7 +23,7 @@ let s:save_cpo = &cpo
 set cpo&vim
 
 function! SyntaxCheckers_go_go_IsAvailable() dict
-    return executable('go') && executable('gofmt')
+    return executable(self.getExec()) && executable('gofmt')
 endfunction
 
 function! SyntaxCheckers_go_go_GetLocList() dict
@@ -50,10 +50,10 @@ function! SyntaxCheckers_go_go_GetLocList() dict
     " Test files, i.e. files with a name ending in `_test.go`, are not
     " compiled by `go build`, therefore `go test` must be called for those.
     if match(expand('%'), '\m_test\.go$') == -1
-        let makeprg = 'go build ' . syntastic#c#NullOutput()
+        let makeprg = self.getExec() . ' build ' . syntastic#c#NullOutput()
         let cleanup = 0
     else
-        let makeprg = 'go test -c ' . syntastic#c#NullOutput()
+        let makeprg = self.getExec() . ' test -c ' . syntastic#c#NullOutput()
         let cleanup = 1
     endif
 

syntax_checkers/go/govet.vim

@@ -19,11 +19,11 @@ let s:save_cpo = &cpo
 set cpo&vim
 
 function! SyntaxCheckers_go_govet_IsAvailable() dict
-    return executable('go')
+    return executable(self.getExec())
 endfunction
 
 function! SyntaxCheckers_go_govet_GetLocList() dict
-    let makeprg = 'go vet'
+    let makeprg = self.getExec() . ' vet'
 
     let errorformat =
         \ '%Evet: %.%\+: %f:%l:%c: %m,' .
@@ -43,7 +43,8 @@ endfunction
 
 call g:SyntasticRegistry.CreateAndRegisterChecker({
     \ 'filetype': 'go',
-    \ 'name': 'govet'})
+    \ 'name': 'govet',
+    \ 'exec': 'go' })
 
 let &cpo = s:save_cpo
 unlet s:save_cpo