Merge bitcoin#29834: build: Change MAC_OSX macro to __APPLE__ in crypto

a71eadf Change MAC_OSX macro to __APPLE__ in crypto package (Lőrinc)

Pull request description:

  Split out from bitcoin#29450 (comment) to avoid the uncertainties and simplify review.

ACKs for top commit:
  theuni:
    ACK a71eadf
  fanquake:
    ACK a71eadf

Tree-SHA512: b6a7bd7ca95585dd9110cefe7c1213f4a1a72bdfc88670abf4a0d9a8bbc12e093544524adce46aa9ca714c472d417f74ca4a678af682ed2488053059434eaa02

src/crypto/sha256.cpp

@@ -20,7 +20,7 @@
 #include <asm/hwcap.h>
 #endif
 
-#if defined(MAC_OSX) && defined(ENABLE_ARM_SHANI)
+#if defined(__APPLE__) && defined(ENABLE_ARM_SHANI)
 #include <sys/types.h>
 #include <sys/sysctl.h>
 #endif
@@ -670,7 +670,7 @@ std::string SHA256AutoDetect(sha256_implementation::UseImplementation use_implem
 #endif
 #endif
 
-#if defined(MAC_OSX)
+#if defined(__APPLE__)
         int val = 0;
         size_t len = sizeof(val);
         if (sysctlbyname("hw.optional.arm.FEAT_SHA256", &val, &len, nullptr, 0) == 0) {