CLib header updates
ROOL authored
Detail:
  assert.h - definition of static_assert
  complex.h - definition of CMPLX[F|L]
  float.h - various implementation defines
  stdio.h - hide gets() as it's been withdrawn
  wchar.h - guard mbstate_t as it can also be in uchar.h, fix missing __valist definition
Admin:
  In order that the functions can be defined in the stubs now (despite not having a compiler to support C11/C18) they are enabled when 'DDE' is defined so that C library builds work.
948e0838