libc: Add membarrier to common seccomp allowed list

Allows ART JIT use membarrier to invalidate instruction
pipelines.

Bug: 66095511
Test: bionic-unit-tests
Change-Id: I8cf83929f00baf5a3c440a899d2667a992bda8e2
diff --git a/libc/SECCOMP_WHITELIST_COMMON.TXT b/libc/SECCOMP_WHITELIST_COMMON.TXT
index 60568e6..f6e9539 100644
--- a/libc/SECCOMP_WHITELIST_COMMON.TXT
+++ b/libc/SECCOMP_WHITELIST_COMMON.TXT
@@ -59,6 +59,9 @@
 # already allowed.
 ssize_t	readlink:readlink(const char *path, char *buf, size_t bufsiz)	arm,x86,x86_64,mips
 
+# Probed for and conditionally used by ART.
+int membarrier(int cmd, int flags) all
+
 # Useful new syscalls which we don't yet use in bionic.
 int sched_getattr(pid_t pid, struct sched_attr* attr, unsigned int flags) all
 int sched_setattr(pid_t pid, struct sched_attr* attr, unsigned int size, unsigned int flags) all