Enable hardware accelerated crc32c for ARM on Linux (#13432)

Summary:
Pull Request resolved: #13432

We've noticed the default CRC32c function gets executed when running on aarch64 cpus within our servers

Issue is that ROCKSDB_AUXV_GETAUXVAL_PRESENT evaluates to false

This fix allows the usage of hardware-accelerated crc32 within our fleet

Reviewed By: jaykorean

Differential Revision: D70423483

fbshipit-source-id: 601da3fbf156e3e40695eb76ee5d37f67f83d427

Author: Nicoshev

util/crc32c_arm64.cc

@@ -10,7 +10,7 @@
 #if defined(__linux__)
 #include <asm/hwcap.h>
 #endif
-#ifdef ROCKSDB_AUXV_GETAUXVAL_PRESENT
+#if defined(ROCKSDB_AUXV_GETAUXVAL_PRESENT) || defined(__linux__)
 #include <sys/auxv.h>
 #endif
 #ifndef HWCAP_CRC32
@@ -52,9 +52,10 @@
 extern bool pmull_runtime_flag;
 
 uint32_t crc32c_runtime_check(void) {
-#if defined(ROCKSDB_AUXV_GETAUXVAL_PRESENT) || defined(__FreeBSD__)
+#if defined(ROCKSDB_AUXV_GETAUXVAL_PRESENT) || defined(__FreeBSD__) || \
+    defined(__linux__)
   uint64_t auxv = 0;
-#if defined(ROCKSDB_AUXV_GETAUXVAL_PRESENT)
+#if defined(ROCKSDB_AUXV_GETAUXVAL_PRESENT) || defined(__linux__)
   auxv = getauxval(AT_HWCAP);
 #elif defined(__FreeBSD__)
   elf_aux_info(AT_HWCAP, &auxv, sizeof(auxv));
@@ -81,9 +82,10 @@ uint32_t crc32c_runtime_check(void) {
 }
 
 bool crc32c_pmull_runtime_check(void) {
-#if defined(ROCKSDB_AUXV_GETAUXVAL_PRESENT) || defined(__FreeBSD__)
+#if defined(ROCKSDB_AUXV_GETAUXVAL_PRESENT) || defined(__FreeBSD__) || \
+    defined(__linux__)
   uint64_t auxv = 0;
-#if defined(ROCKSDB_AUXV_GETAUXVAL_PRESENT)
+#if defined(ROCKSDB_AUXV_GETAUXVAL_PRESENT) || defined(__linux__)
   auxv = getauxval(AT_HWCAP);
 #elif defined(__FreeBSD__)
   elf_aux_info(AT_HWCAP, &auxv, sizeof(auxv));