Combine consecutive inline asm instructions into one statement to

Combine consecutive inline asm instructions into one statement to
prevent them from being reordered.
The GCC manual states:
| Similarly, you can't expect a sequence of volatile asm instructions
| to remain perfectly consecutive. If you want consecutive output, use a
| single asm. Also, GCC will perform some optimizations across a
| volatile asm instruction; GCC does not “forget everything” when it
| encounters a volatile asm instruction the way some other compilers do.