ocaml syntax: fix linting of functor and functor params

The `module` keyword is now treated uniformly. Previously, it was
matched differently in signatures (matchgroup `ocamlModSpec`) than
elsewhere (matchgroup `ocamlModule`). Both cases have almost identical
syntax:

    (* in signatures: *)
    module M (X1 : T1) … (Xn: Tn) : MODULE TYPE
    (* in structures: *)
    module M (X1 : T1) … (Xn: Tn) [: MODULE TYPE] = MODULE DEF

The case distinction was not taking profit of the small difference in
syntax, and it was creating complexity and mismatch between both cases.
Each case had shortcomings.

In signatures, functor parameters like this where not highlighted
corrrectly:

    (* in signatures: *)
    module M (X1 : T1) : …

Also, the only case where the `functor` keyword was highlighted
correctly was in a `module` type annotation *in a signature*. It was not
highlighted correctly in `module` type annotations *in structures*, nor
in `module` definitions, nor in `module type` definitions.

    (* in signatures: *)
    module type T = functor (X1 : T1) -> …
    module M : functor (X1 : T1) -> …  (* the only case that was working *)
    (* in structures: *)
    module type T = functor (X1 : T1) -> …
    module M : functor (X1 : T1) -> … = …
    module M = functor (X1 : T1) -> …

These bugs are now fixed. The `ocamlModule` matchgroup subsumes the
features of both former cases (`module` in signatures / in structures).
The `functor` keyword is no more "contained", so that it now matches in
all of the 5 situations above.

Author: Maelan

syntax/ocaml.vim

@@ -77,7 +77,7 @@ syn match    ocamlKwErr  "\<\(mutable\|nonrec\|of\|private\)\>"
 syn cluster  ocamlAllErrs contains=@ocamlAENoParen,ocamlParenErr
 syn cluster  ocamlAENoParen contains=ocamlBraceErr,ocamlBrackErr,ocamlCountErr,ocamlDoErr,ocamlDoneErr,ocamlEndErr,ocamlThenErr,ocamlKwErr
 
-syn cluster  ocamlContained contains=ocamlTodo,ocamlPreDef,ocamlModParam,ocamlModParam1,ocamlMPRestr,ocamlMPRestr2,ocamlModRHS,ocamlFuncWith,ocamlModTypeRestr,ocamlModTRWith,ocamlWith,ocamlWithRest,ocamlModType,ocamlFullMod,ocamlVal
+syn cluster  ocamlContained contains=ocamlTodo,ocamlPreDef,ocamlModParam,ocamlModParam1,ocamlMPRestr,ocamlModRHS,ocamlFuncWith,ocamlModTypeRestr,ocamlModTRWith,ocamlWith,ocamlWithRest,ocamlModType,ocamlFullMod,ocamlVal
 
 
 " Enclosing delimiters
@@ -128,16 +128,14 @@ syn match   ocamlKeyword "\<open\>" skipwhite skipempty nextgroup=ocamlFullMod
 syn match    ocamlKeyword "\<include\>" skipwhite skipempty nextgroup=ocamlModParam,ocamlFullMod
 
 " "module" - somewhat complicated stuff ;-)
-syn region   ocamlModSpec matchgroup=ocamlKeyword start="\<module\>" matchgroup=ocamlModule end="\<\u\(\w\|'\)*\>" contained contains=@ocamlAllErrs,ocamlComment skipwhite skipempty nextgroup=ocamlModTRWith,ocamlMPRestr
 syn region   ocamlModule matchgroup=ocamlKeyword start="\<module\>" matchgroup=ocamlModule end="\<\u\(\w\|'\)*\>" contains=@ocamlAllErrs,ocamlComment skipwhite skipempty nextgroup=ocamlPreDef
-syn region   ocamlPreDef start="."me=e-1 matchgroup=ocamlKeyword end="\l\|=\|)"me=e-1 contained contains=@ocamlAllErrs,ocamlComment,ocamlModParam,ocamlGenMod,ocamlModTypeRestr,ocamlModTRWith nextgroup=ocamlModPreRHS
+syn region   ocamlPreDef start="."me=e-1 end="[a-z:=)]\@=" contained contains=@ocamlAllErrs,ocamlComment,ocamlModParam,ocamlGenMod,ocamlModTypeRestr nextgroup=ocamlMPRestr,ocamlModPreRHS
 syn region   ocamlModParam start="(\*\@!" end=")" contained contains=ocamlGenMod,ocamlModParam,ocamlModParam1,ocamlSig,ocamlVal
 syn match    ocamlModParam1 "\<\u\(\w\|'\)*\>" contained skipwhite skipempty
 syn match    ocamlGenMod "()" contained skipwhite skipempty
 
-syn region   ocamlMPRestr start=":" end="."me=e-1 contained contains=@ocamlComment skipwhite skipempty nextgroup=ocamlSig,ocamlMPRestr2,ocamlModTypeRestr,ocamlModTypeOf
+syn match    ocamlMPRestr ":" contained skipwhite skipempty nextgroup=ocamlModTRWith,ocamlSig,ocamlMPRestr2,ocamlModTypeRestr,ocamlModTypeOf
 syn match    ocamlModTypeRestr "\<\w\(\w\|'\)*\( *\. *\w\(\w\|'\)*\)*\>" contained
-syn region   ocamlMPRestr2 start="\<functor\>" matchgroup=ocamlKeyword end="->" contained contains=@ocamlAllErrs,ocamlComment,ocamlModParam,ocamlGenMod skipwhite skipempty nextgroup=ocamlFuncWith,ocamlMPRestr2
 syn match    ocamlModPreRHS "=" contained skipwhite skipempty nextgroup=ocamlModParam,ocamlFullMod
 syn keyword  ocamlKeyword val
 syn region   ocamlVal matchgroup=ocamlKeyword start="\<val\>" matchgroup=ocamlLCIdentifier end="\<\l\(\w\|'\)*\>" contains=@ocamlAllErrs,ocamlComment,ocamlFullMod skipwhite skipempty nextgroup=ocamlMPRestr
@@ -146,15 +144,18 @@ syn match    ocamlFullMod "\<\u\(\w\|'\)*\( *\. *\u\(\w\|'\)*\)*" contained skip
 
 syn region   ocamlFuncWith start="([*)]\@!" end=")" contained contains=ocamlComment,ocamlWith,ocamlStruct skipwhite skipempty nextgroup=ocamlFuncWith
 
-syn region   ocamlModTRWith start=":\s*(\*\@!"hs=s+1 end=")" contained contains=@ocamlAENoParen,ocamlWith
+syn region   ocamlModTRWith start="(\*\@!" end=")" contained contains=@ocamlAENoParen,ocamlWith
 syn match    ocamlWith "\<\(\u\(\w\|'\)* *\. *\)*\w\(\w\|'\)*\>" contained skipwhite skipempty nextgroup=ocamlWithRest
 syn region   ocamlWithRest start="[^)]" end=")"me=e-1 contained contains=ALLBUT,@ocamlContained
 
 " "struct"
 syn region   ocamlStruct matchgroup=ocamlStructEncl start="\<\(module\s\+\)\=struct\>" matchgroup=ocamlStructEncl end="\<end\>" contains=ALLBUT,@ocamlContained,ocamlEndErr
 
 " "sig"
-syn region   ocamlSig matchgroup=ocamlSigEncl start="\<sig\>" matchgroup=ocamlSigEncl end="\<end\>" contains=ALLBUT,@ocamlContained,ocamlEndErr,ocamlModule
+syn region   ocamlSig matchgroup=ocamlSigEncl start="\<sig\>" matchgroup=ocamlSigEncl end="\<end\>" contains=ALLBUT,@ocamlContained,ocamlEndErr
+
+" "functor"
+syn region   ocamlMPRestr2 start="\<functor\>" matchgroup=ocamlKeyword end="->" contains=@ocamlAllErrs,ocamlComment,ocamlModParam,ocamlGenMod skipwhite skipempty nextgroup=ocamlStruct,ocamlSig,ocamlFuncWith,ocamlMPRestr2
 
 " "module type"
 syn region   ocamlModTypeOf start="\<module\s\+type\(\s\+of\)\=\>" matchgroup=ocamlModule end="\<\w\(\w\|'\)*\>" contains=ocamlComment skipwhite skipempty nextgroup=ocamlMTDef