[perlasm] Hide OPENSSL_armcap_P in assembly

This CL changes adds a ".hidden OPENSSL_armcap_P" statement to the
".comm OPENSSL_armcap_P" statements for the sha*-armv8.pl files,
similar to what was doen for the sha*-armv4.pl files in CL 3471.

Change-Id: I524b3dce7e5cfe017498847fbf9b8a5df4b98fce
Reviewed-on: https://boringssl-review.googlesource.com/c/32324
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>

crypto/fipsmodule/sha/asm/sha1-armv8.pl

diff --git a/crypto/fipsmodule/sha/asm/sha1-armv8.pl b/crypto/fipsmodule/sha/asm/sha1-armv8.pl
index cec3669..80567d9 100644
--- a/crypto/fipsmodule/sha/asm/sha1-armv8.pl
+++ b/crypto/fipsmodule/sha/asm/sha1-armv8.pl
@@ -330,6 +330,7 @@
 .asciz	"SHA1 block transform for ARMv8, CRYPTOGAMS by <appro\@openssl.org>"
 .align	2
 .comm	OPENSSL_armcap_P,4,4
+.hidden	OPENSSL_armcap_P
 ___
 }}}
 

crypto/fipsmodule/sha/asm/sha512-armv8.pl

diff --git a/crypto/fipsmodule/sha/asm/sha512-armv8.pl b/crypto/fipsmodule/sha/asm/sha512-armv8.pl
index e3244f7..22c47d7 100644
--- a/crypto/fipsmodule/sha/asm/sha512-armv8.pl
+++ b/crypto/fipsmodule/sha/asm/sha512-armv8.pl
@@ -428,6 +428,7 @@
 $code.=<<___;
 #ifndef	__KERNEL__
 .comm	OPENSSL_armcap_P,4,4
+.hidden	OPENSSL_armcap_P
 #endif
 ___