Catch up with changes made on amd64 (kettenis@):

Catch up with changes made on amd64 (kettenis@):

Generating mixed 16-bit/32-bit/64-bit code with clang's integrated
assembler is a bit tricky.  It supports the .code16, .code32 and
.code64 directives.  But it doesn't know about the data16/data32 and
addr16/addr32 instruction prefixes.  Instead it tries to determine
those from the instruction opcode.  It mostly succeeds, but there are
a couple of corner cases where clang will generate the "addr32" form
where gas generates the "addr16" form in .code16 segments.  That
should be no problem (and just waste a couple of bytes), but it makes
comparing the generated code a bit difficult.

Allow the trampoline code to be compiled with both.  For clang #define
away the addr32 prefix and avoid using the data32 prefix by using a
mnemonic that explicitly encodes the size of the operand.  Add a few
addr32 prefixes in .code16 blocks to reduce the differences between
code generated by clang and gas.

ok deraadt@