Incorrect problem matcher for ocaml >= 4.09

[Khady]

I sent a change to the OCaml compiler to change the format of the error messages ocaml/ocaml#8541. It means that messages printed by OCaml >= 4.09 won't be parsed properly by this LSP server.

The change affects the messages that are on multiple lines. The message now contains the first and last lines. Also the second part of the characters section is no longer a byte offset, it is the position on the last line.

Here is an exemple.

File "robustmatch.ml", lines 33-37, characters 6-23:
 9 | ......match t1, t2, x with
10 |       | AB, AB, A -> ()
11 |       | MAB, _, A -> ()
12 |       | _,  AB, B -> ()
13 |       | _, MAB, B -> ()
Warning 8: this pattern-matching is not exhaustive.
Here is an example of a case that is not matched:
(AB, MAB, A)

The code to change seems to be in package.json:

vscode-reasonml/package.json

Lines 287 to 294 in ecf71d7

	{
	"regexp":
	"^\\s*\\bFile\\b\\s*\"(.*)\",\\s*\\bline\\b\\s*(\\d+),\\s*\\bcharacters\\b\\s*(\\d+)-(\\d+)\\s*:\\s*$",
	"file": 1,
	"line": 2,
	"column": 3,
	"endColumn": 4
	},

Tuareg has a list of compilation messages that can be used for reference: https://github.com/Chris00/tuareg/blob/master/compilation.txt