For now, support locking only for linux targets that are different from
riscv* where the target depends on libatomic (and fails during
bootstrap).
PR lto/106170
lto-plugin/ChangeLog:
* configure.ac: Configure HAVE_PTHREAD_LOCKING.
* lto-plugin.c (LOCK_SECTION): New.
(UNLOCK_SECTION): New.
(claim_file_handler): Use the newly added macros.
(onload): Likewise.
* config.h.in: Regenerate.
* configure: Regenerate.
Martin Liska
d89fa97ff3