makedepend would crash when a source includes a header indirectly, such
as
#define HEADER "some-header.h"
#include HEADER
Do not define HEADER (makedepend would detects this as an incomplete
include) and add the dependency manually in the Makefile.
This should hopefully fix bug #33374.
The preprocessor magic in mapi was nothing but obfuscation. Rewrite
mapi_abi.py to generate real C code.
This commit removes the hack added in
43121f2086.