crypto/bn/*: x86[_64] division instruction doesn't handle constants, change constraint from 'g' to 'rm'.

(Imported from upstream's 2a20b6d973)

Change-Id: If3db4dac3d4cd675cf7854c4e154823d25d00eb9
Reviewed-on: https://boringssl-review.googlesource.com/10921
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>

crypto/bn/div.c

@@ -158,13 +158,13 @@ static inline void bn_div_rem_words(BN_ULONG *quotient_out, BN_ULONG *rem_out,
   __asm__ volatile (
     "divl %4"
     : "=a"(*quotient_out), "=d"(*rem_out)
-    : "a"(n1), "d"(n0), "g"(d0)
+    : "a"(n1), "d"(n0), "rm"(d0)
     : "cc" );
 #elif !defined(OPENSSL_NO_ASM) && defined(OPENSSL_X86_64) && defined(__GNUC__)
   __asm__ volatile (
     "divq %4"
     : "=a"(*quotient_out), "=d"(*rem_out)
-    : "a"(n1), "d"(n0), "g"(d0)
+    : "a"(n1), "d"(n0), "rm"(d0)
     : "cc" );
 #else
 #if defined(BN_ULLONG)