Consensus: Fix bug when compiler do not support __builtin_clz*

#ifdef is not correct since defination is defined to 0 or 1. Should change to #if

Github-Pull: #12573
Rebased-From: 18307849b405f9e2067eaa8091b105838f413707

src/crypto/common.h

@@ -82,12 +82,12 @@ void static inline WriteBE64(unsigned char* ptr, uint64_t x)
 /** Return the smallest number n such that (x >> n) == 0 (or 64 if the highest bit in x is set. */
 uint64_t static inline CountBits(uint64_t x)
 {
-#ifdef HAVE_DECL___BUILTIN_CLZL
+#if HAVE_DECL___BUILTIN_CLZL
     if (sizeof(unsigned long) >= sizeof(uint64_t)) {
         return x ? 8 * sizeof(unsigned long) - __builtin_clzl(x) : 0;
     }
 #endif
-#ifdef HAVE_DECL___BUILTIN_CLZLL
+#if HAVE_DECL___BUILTIN_CLZLL
     if (sizeof(unsigned long long) >= sizeof(uint64_t)) {
         return x ? 8 * sizeof(unsigned long long) - __builtin_clzll(x) : 0;
     }