Merge #13611: [bugfix] Use __cpuid_count for gnu C to avoid gitian build fail.

63c16ed507 Use __cpuid_count for gnu C to avoid gitian build fail. (Chun Kuan Lee)

Pull request description:

  Fixes #13538

Tree-SHA512: 161ae4db022288ae8631a166eaea2d08cf2c90bcd27218a094a754276de30b92ca9cfb5a79aa899c5a9d0534c5d7261037e7e915e1b92bc7067ab1539dc2b51e

src/crypto/sha256.cpp

@@ -9,7 +9,7 @@
 #include <string.h>
 #include <atomic>
 
-#if defined(__x86_64__) || defined(__amd64__)
+#if defined(__x86_64__) || defined(__amd64__) || defined(__i386__)
 #if defined(USE_ASM)
 #include <cpuid.h>
 namespace sha256_sse4
@@ -534,7 +534,11 @@ bool SelfTest() {
 // We can't use cpuid.h's __get_cpuid as it does not support subleafs.
 void inline cpuid(uint32_t leaf, uint32_t subleaf, uint32_t& a, uint32_t& b, uint32_t& c, uint32_t& d)
 {
+#ifdef __GNUC__
+    __cpuid_count(leaf, subleaf, a, b, c, d);
+#else
   __asm__ ("cpuid" : "=a"(a), "=b"(b), "=c"(c), "=d"(d) : "0"(leaf), "2"(subleaf));
+#endif
 }
 
 /** Check whether the OS has enabled AVX registers. */