Fix for Mantis #17598. When extended syntax is off allow the result of constructors to be dropped when the constructor is called as an instance method instead of a class method.

pstatmnt.pas, statement:
  * check whether the constructor is called as an instance or class method
nflw.pas, tlabelnode.pass_1:
  * don't check the owner of the labelsym when there is none (happens with internally created labels like for e.g. exception handling)

+ added test  

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@25068 3ad0048d-3df7-0310-abae-a5850022a9f2
Fix for Mantis #24651. Allow pointer comparison for internal expressions (in this case check for valid VMT).

nadd.pas, taddnode:
  + add new constructor "create_internal" which adds "nf_internal" to the node's "flags"
  * pass_typecheck_internal: allow pointer comparisons other than "=" and "<>" for nodes which have "nf_internal" set
psub.pas, generate_bodyentry_block:
  * create the addnode using "create_internal" instead of "create" to allow the pointer comparison

+ added test 

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@25069 3ad0048d-3df7-0310-abae-a5850022a9f2