Add 3rd argument register to X86.

Implement more instructions.

Change-Id: I3af7bbaf18eedc6537f1cfc2d57c4f6106fb5164
diff --git a/src/globals.h b/src/globals.h
index 4300a6e..0cf4260 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -46,6 +46,9 @@
 // Required ARM instruction alignment
 const int kArmAlignment = 4;
 
+// Required X86 instruction alignment
+const int kX86Alignment = 16;
+
 // System page size.  Normally you're expected to get this from
 // sysconf(_SC_PAGESIZE) or some system-specific define (usually
 // PAGESIZE or PAGE_SIZE).  If we use a simple compile-time constant