test: nasm-t -- Add zerobyte test

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>

travis/test/zerobyte.asm

@@ -0,0 +1,21 @@
+	bits 64
+
+	mov eax,bar-foo
+
+foo:
+	add al,r10b
+bar:
+
+	lldt ax
+	lldt r8w
+	ltr [rax]
+	sldt eax
+	sldt r8d
+	str eax
+	str rax
+	str r8d
+	str r8
+	verr ax
+	verr r8w
+	verw ax
+	verw r8w

travis/test/zerobyte.json

@@ -0,0 +1,11 @@
+[
+	{
+		"description": "Test for accidental duplication of REX prefixes",
+		"id": "zerobyte",
+		"format": "bin",
+		"source": "zerobyte.asm",
+		"target": [
+			{ "output": "zerobyte.bin" }
+		]
+	}
+]