Added MBED_STATIC_ASSERT for compile-time assertions, results in
compile-time error if condition is false
The assertion acts as a declaration that can be placed at file scope, in
a code block (except after a label), or as a member of
a C++ class/struct/union.
Unfortunately, there does not exist a backup construct for use in
C class/struct/union contexts. An alternative macro,
MBED_STRUCT_STATIC_ASSERT provides this ability to avoid disabling
static assertions for the majority of mbed-supported C compilers.
Christopher Haster