Fix the mscs tests on Windows, and use the improved Simplify for all tests instead.

test/handler/test_ghc_handler.vader

@@ -48,11 +48,11 @@ Execute(The ghc handler should handle ghc 8 output):
   \ ],
   \ ale#handlers#haskell#HandleGHCFormat(bufnr(''), [
   \ '',
-  \ ale#path#Winify('src/Appoint/Lib.hs') . ':6:1: error:',
+  \ ale#path#Simplify('src/Appoint/Lib.hs') . ':6:1: error:',
   \ '    Failed to load interface for ‘GitHub.Data’',
   \ '    Use -v to see a list of the files searched for.',
   \ '',
-  \ ale#path#Winify('src/Appoint/Lib.hs') . ':7:1: warning:',
+  \ ale#path#Simplify('src/Appoint/Lib.hs') . ':7:1: warning:',
   \ '    Failed to load interface for ‘GitHub.Endpoints.PullRequests’',
   \ '    Use -v to see a list of the files searched for.',
   \ ])
@@ -92,12 +92,12 @@ Execute(The ghc handler should handle ghc 7 output):
   \   },
   \ ],
   \ ale#handlers#haskell#HandleGHCFormat(bufnr(''), [
-  \ ale#path#Winify('src/Main.hs') . ':168:1:',
+  \ ale#path#Simplify('src/Main.hs') . ':168:1:',
   \ '    parse error (possibly incorrect indentation or mismatched brackets)',
-  \ ale#path#Winify('src/Main.hs') . ':84:1:Warning:',
+  \ ale#path#Simplify('src/Main.hs') . ':84:1:Warning:',
   \ '    Top-level binding with no type signature:',
   \ '    myLayout :: Choose Tall (Choose (Mirror Tall) Full) a',
-  \ ale#path#Winify('src/Main.hs') . ':94:5:Error:',
+  \ ale#path#Simplify('src/Main.hs') . ':94:5:Error:',
   \ '  Some other error',
   \ ])
 
@@ -122,7 +122,7 @@ Execute(The ghc handler should handle stack 1.5.1 output):
   \   },
   \ ],
   \ ale#handlers#haskell#HandleGHCFormat(bufnr(''), [
-  \   '    ' . ale#path#Winify('src/Main.hs') . ':160:14: error:',
+  \   '    ' . ale#path#Simplify('src/Main.hs') . ':160:14: error:',
   \   '        • Expecting one fewer arguments to ‘Exp’',
   \   '          Expected kind ‘k0 -> *’, but ‘Exp’ has kind ‘*’',
   \   '        • In the type ‘Exp a’',