gprofng: remove unused functions, duplicate macros

class Reloc is not used after commit
13f614be23a gprofng: Refactor readSymSec for using BFD's asymbol struct

Many common macros were defined in different sources.
Sometimes a macro was used, sometimes a macros value was used.
Removed unused macros and include files.

gprofng/ChangeLog
2025-05-03  Vladimir Mezentsev  <vladimir.mezentsev@oracle.com>

	* common/gp-experiment.h: Define variables that are passed to
	libcollector. Remove unused macros.
	* libcollector/collector.c: Cleanup macros.
	* libcollector/descendants.h: Likewise.
	* libcollector/envmgmt.c: Likewise.
	* libcollector/linetrace.c: Likewise.
	* src/collect.h: Likewise.
	* src/envsets.cc: Likewise.
	* src/gp-collect-app.cc: Likewise.
	* src/Stabs.cc: Remove class Reloc.
	* src/Stabs.h: Likewise.
	* src/ipcio.cc: Remove unused include files.