linux: Make profil_counter a compat_symbol (BZ#17726)

As indicated by Joseph's comment on BZ#17726, this symbol is most
likely a historical ABI accident.  This patch make it on both arm
and sparc ABIs a compat_symbol.

Checked against a build arm-linux-gnueabihf, sparcv9-linux-gnu, adn
sparc64-linux-gnu to see if the symbol is still present.

	* gmon/Versions (libc) [GLIBC_2.31]: New entry.
	* sysdeps/unix/sysv/linux/arm/profil-counter.h (profil_counter):
	Make a compat_symbol.
	* sysdeps/unix/sysv/linux/sparc/profil-counter.h
	(__profil_counter_global): Likewise.

ChangeLog

@@ -1,6 +1,12 @@
 2019-08-23  Adhemerval Zanella  <adhemerval.zanella@linaro.org>
 	    Florian Weimer  <fweimer@redhat.com>
 
+	* gmon/Versions (libc) [GLIBC_2.31]: New entry.
+	* sysdeps/unix/sysv/linux/arm/profil-counter.h (profil_counter):
+	Make a compat_symbol.
+	* sysdeps/unix/sysv/linux/sparc/profil-counter.h
+	(__profil_counter_global): Likewise.
+
 	* debug/segfault.c (install_handler): Use SA_SIGINFO if defined.
 	* sysdeps/generic/profil-counter.h (__profil_counter): Cast to
 	uintptr_t.

gmon/Versions

@@ -19,4 +19,6 @@ libc {
   GLIBC_2.2.3 {
     sprofil;
   }
+  GLIBC_2.31 {
+  }
 }

sysdeps/unix/sysv/linux/arm/profil-counter.h

@@ -30,5 +30,8 @@ __profil_counter (int signo, siginfo_t *_si, void *scp)
   asm volatile ("");
 }
 #ifndef __profil_counter
-weak_alias (__profil_counter, profil_counter)
+# include <shlib-compat.h>
+# if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_31)
+compat_symbol (libc, __profil_counter, profil_counter, GLIBC_2_0);
+# endif
 #endif

sysdeps/unix/sysv/linux/sparc/profil-counter.h

@@ -21,6 +21,8 @@
 #include <sysdeps/unix/sysv/linux/profil-counter.h>
 
 #ifndef __profil_counter
+# include <shlib-compat.h>
+# if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_31)
 void
 __profil_counter_global (int signo, struct sigcontext *si)
 {
@@ -30,5 +32,6 @@ __profil_counter_global (int signo, struct sigcontext *si)
   profil_count (si->si_regs.pc);
 #endif
 }
-weak_alias (__profil_counter_global, profil_counter)
+compat_symbol (libc, __profil_counter_global, profil_counter, GLIBC_2_0);
+# endif
 #endif