Fix build on arm64 architectures with some strict compilers

This patch fixes an issue that occurs on 64-bit architetures under
strict compiler rules. The code initially checked that the received
size stored in 'uint64_t' was not bigger than the max value of a
'size_t' variable, which is legitimate on 32-bit architectures where
'size_t' variables are stored on 32 bits. On 64-bit architectures,
this test no longer makes sense since 'uint64_t' and 'size_t' types
have the same size. The issue is fixed by ignoring this portion
of code when built for arm64.

src/v1_decoder.cpp

@@ -111,11 +111,13 @@ int zmq::v1_decoder_t::eight_byte_size_ready (unsigned char const *)
         return -1;
     }
 
+#ifndef __aarch64__
     //  Message size must fit within range of size_t data type.
     if (payload_length - 1 > std::numeric_limits<size_t>::max ()) {
         errno = EMSGSIZE;
         return -1;
     }
+#endif
 
     const size_t msg_size = static_cast<size_t> (payload_length - 1);