Change __BORLANDC__ to BOOST_BORLANDC, which is defined in Boost config for the Embarcadero non-clang-based compilers.

include/boost/integer/common_factor_ct.hpp

@@ -30,7 +30,7 @@ namespace detail
         BOOST_STATIC_CONSTANT( static_gcd_type, new_value1 = Value2 );
         BOOST_STATIC_CONSTANT( static_gcd_type, new_value2 = Value1 % Value2 );
 
-        #ifndef __BORLANDC__
+        #ifndef BOOST_BORLANDC
         #define BOOST_DETAIL_GCD_HELPER_VAL(Value) static_cast<static_gcd_type>(Value)
         #else
         typedef static_gcd_helper_t  self_type;

include/boost/integer/integer_log2.hpp

@@ -16,7 +16,7 @@
 #define BOOST_INTEGER_INTEGER_LOG2_HPP
 
 #include <assert.h>
-#ifdef __BORLANDC__
+#if defined(__BORLANDC__) && !defined(__clang__)
 #include <climits>
 #endif
 #include <boost/limits.hpp>
@@ -75,7 +75,7 @@ namespace boost {
   template <typename T>
   struct width {
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
       BOOST_STATIC_CONSTANT(int, value = sizeof(T) * CHAR_BIT);
 #else
       BOOST_STATIC_CONSTANT(int, value = (std::numeric_limits<T>::digits));