Implement DECLARED() for generic symbols. This fixes Mantis #21829 . The syntax is SomeGenericType<> for a generic with only one type parameter and SomeGeneric<,[,]*> for a generic with more than one type parameter. Spaces between the commas or brackets are allowed.

scanner.pas, parse_compiler_expr.read_factor:
  + allow "<>" after "declared" (handle "<>" operator specially)
  + count "," to get correct amount of type parameters
  + check together with the count string for symbols 
  + correctly handle dummy symbols

+ added tests

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@23544 3ad0048d-3df7-0310-abae-a5850022a9f2