fix static linking of pthread apps

When compiling python you get duplicate symbol problem.
Seen in the autobuilders of buildroot project.

libc/sysdeps/linux/common/setregid.c

@@ -37,4 +37,4 @@ int setregid(gid_t rgid, gid_t egid)
 }
 #endif
 
-libc_hidden_def(setregid)
+libc_hidden_weak(setregid)

libc/sysdeps/linux/common/setresgid.c

@@ -16,7 +16,7 @@
 # define __NR_setresgid __NR_setresgid32
 
 _syscall3(int, setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
-libc_hidden_def(setresgid)
+libc_hidden_weak(setresgid)
 
 #elif defined(__NR_setresgid)
 
@@ -34,7 +34,7 @@ int setresgid(gid_t rgid, gid_t egid, gid_t sgid)
 	}
 	return (__syscall_setresgid(rgid, egid, sgid));
 }
-libc_hidden_def(setresgid)
+libc_hidden_weak(setresgid)
 
 #endif
 

libc/sysdeps/linux/common/setresuid.c

@@ -16,7 +16,7 @@
 # define __NR_setresuid __NR_setresuid32
 
 _syscall3(int, setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
-libc_hidden_def(setresuid)
+libc_hidden_weak(setresuid)
 
 #elif defined(__NR_setresuid)
 
@@ -34,7 +34,7 @@ int setresuid(uid_t ruid, uid_t euid, uid_t suid)
 	}
 	return (__syscall_setresuid(ruid, euid, suid));
 }
-libc_hidden_def(setresuid)
+libc_hidden_weak(setresuid)
 
 #endif