Register the UnicodeString keyword handler

TmwBasePasLex.Func158 lexes UnicodeString as ptString with ExID
ptUnicodeString, the way Func-handlers already treat AnsiString and
WideString, but InitIdent never put it in FIdentFuncTable. 'UnicodeString'
hashes to 158, which had no entry, so the handler was unreachable (Delphi:
H2219 Private symbol 'Func158' declared but never used) and the word lexed
as a plain identifier.

Declarations parse the same either way. The difference is a typecast:
UnicodeString(p^) built a CALL whose callee was an IDENTIFIER, which
cannot be told apart from a call to a routine of that name, while
AnsiString(p^) and WideString(p^) build a TYPE callee. Now all three do.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: Partouf

Source/SimpleParser/SimpleParser.Lexer.pas

@@ -574,6 +574,7 @@ procedure TmwBasePasLex.InitIdent;
       141: FIdentFuncTable[I] := Func141;
       142: FIdentFuncTable[I] := Func142;
       143: FIdentFuncTable[I] := Func143;
+      158: FIdentFuncTable[I] := Func158;
       166: FIdentFuncTable[I] := Func166;
       167: FIdentFuncTable[I] := Func167;
       168: FIdentFuncTable[I] := Func168;