Make dis-asm.h handle being included outside an 'extern "C"' block;
this allows us to remove the 'extern "C"' blocks that our two C++
files that include it are using.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2c316f9af4