Remove old masm workaround.

This dates to ded93581f1674f81faa0dba4b15a842756066ab2, but we have
since switched to building with nasm, to match upstream's supported
assemblers. Since this doesn't affect anything we generate, remove the
workaround to reduce the diff against upstream.

Change-Id: I549ae97ad6d6f28836f6c9d54dcf51c518de7521
Reviewed-on: https://boringssl-review.googlesource.com/15986
Reviewed-by: Adam Langley <agl@google.com>

crypto/perlasm/x86_64-xlate.pl

diff --git a/crypto/perlasm/x86_64-xlate.pl b/crypto/perlasm/x86_64-xlate.pl
index 6043bc7..6a9b246 100755
--- a/crypto/perlasm/x86_64-xlate.pl
+++ b/crypto/perlasm/x86_64-xlate.pl
@@ -1194,13 +1194,7 @@
 		}
 		@args = reverse(@args);
 		undef $sz if ($nasm && $opcode->mnemonic() eq "lea");
-
-		if ($insn eq "movq" && $#args == 1 && $args[0]->out($sz) eq "xmm0" && $args[1]->out($sz) eq "rax") {
-		    # I have no clue why MASM can't parse this instruction.
-		    printf "DB 66h, 48h, 0fh, 6eh, 0c0h";
-		} else {
-		    printf "\t%s\t%s",$insn,join(",",map($_->out($sz),@args));
-		}
+		printf "\t%s\t%s",$insn,join(",",map($_->out($sz),@args));
 	    }
 	} else {
 	    printf "\t%s",$opcode->out();