Unhide __pthread_cleanup_push and __pthread_cleanup_pop for 64-bit ABIs

Note that unwanted-symbols/{x86_64,mips64}/libc.so.functions.txt symlink
to arm64/libc.so.functions.txt

Change-Id: I9a2ebb0b810fe7396d7d546a877b59233a1fd7a8
diff --git a/build/tools/unwanted-symbols/arm64/libc.so.functions.txt b/build/tools/unwanted-symbols/arm64/libc.so.functions.txt
index 7bd76d6..a6cad79 100644
--- a/build/tools/unwanted-symbols/arm64/libc.so.functions.txt
+++ b/build/tools/unwanted-symbols/arm64/libc.so.functions.txt
@@ -16,8 +16,6 @@
 localtime_tz
 mktime_tz
 posix2time
-__pthread_cleanup_pop
-__pthread_cleanup_push
 __pthread_gettid
 SHA1Final
 SHA1Init