You can probably work around that by adding
e32def.h:2769: error: initializer element is not constant
to the mmp-files. Or then, if you don't want to touch the mmp-files, you can edit e32def.h and simply comment out the assignment.
Note that I originally used gcce for building Apache and there was a number of problems that needed to be worked around. Initially a gcce built Apache simply did not run. So, when you get php to build, you may be in for some debugging before it loads and runs.
static const char* const KSuppressPlatSecDiagnostic; // = KSuppressPlatSecDiagnosticMagicValue;