gprofng: fix build issues on musl

gprofng/ChangeLog
2022-09-14  Vladimir Mezentsev  <vladimir.mezentsev@oracle.com>

	PR gprofng/29477
	* configure.ac: Set __MUSL_LIBC.
	* configure: Rebuild.
	* common/config.h.in: Rebuild.
	* src/collector_module.h: Fix compiler errors because mmap64, open64,
	pwrite64 are macros and getcontext() is absent on musl.
	* libcollector/collector.c: Likewise.
	* libcollector/hwprofile.c: Likewise.
	* libcollector/iolib.c: Likewise.
	* libcollector/libcol_util.c: Likewise.
	* libcollector/linetrace.c: Likewise.
	* libcollector/memmgr.c: Likewise.
	* libcollector/profile.c: Likewise.
	* libcollector/unwind.c: Likewise.
	* libcollector/dispatcher.c: Likewise.
	* src/Experiment.cc: Likewise.
	* libcollector/collector.h: Use dlsym() because dlvsym() is not defined
	on musl.
	* libcollector/iotrace.c: Remove interposition of versioned functions.
	* libcollector/mmaptrace.c: Likewise.
	* libcollector/libcol_util.h: Fix -Wint-to-pointer-cast warnings.
	* libcollector/jprofile.c: Likewise.
	* libcollector/synctrace.c: Include "collector.h".
	* src/Print.cc: Use get_basename() because basename() is not defined
	on musl.
	* common/hwcdrv.c: Fix -Wformat= warnings.