+ Support dynamic copy relocations.
* For unresolved weak symbols, provide dynamic binding only if they are referenced via GOT or PLT (ld-compatible behavior).
* Made more TElfExeOutput properties/methods usable by descendant classes.
* x86_64/cpuelf.pas: some refactoring, handle DTPOFF relocations, prohibit TPOFF relocations in shared objects.
* i386/cpuelf.pas: set symref_from_text flags for copy relocations to work correctly.

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@23375 3ad0048d-3df7-0310-abae-a5850022a9f2