/usr/include/AvailabilityInternal.h:4098:10: error:

Question

I have recently updated the Xcode.
When I try to compile a c code (xsfconvert) I get the following error
make
cpp  -DPROGNAME='"lm2xsf"' lm_main.c  tmp.c
In file included from lm_main.c:17:
In file included from ./lm_all.h:16:
In file included from /usr/include/stdio.h:65:
In file included from /usr/include/Availability.h:148:
/usr/include/AvailabilityInternal.h:4098:10: error: #else without #if
        #else
         ^
/usr/include/AvailabilityInternal.h:4158:10: error: unterminated conditional directive
        #if __MAC_OS_X_VERSION_MIN_REQUIRED >= __MAC_10_6
         ^
/usr/include/AvailabilityInternal.h:4131:10: error: unterminated conditional directive
        #if __MAC_OS_X_VERSION_MIN_REQUIRED >= __MAC_10_5
         ^
/usr/include/AvailabilityInternal.h:4108:10: error: unterminated conditional directive
        #if __MAC_OS_X_VERSION_MIN_REQUIRED >= __MAC_10_4
         ^
4 errors generated.
make: *** [lm_main.o] Error 1
Since this is an Apple distributed file, I am reluctant to fix the error myself. What is wrong? The strange nested ifs are intentional? Or my Xcode update through app-store went wrong somehow?
update:
I have installed fink compilers, and they do work. Thus, I conclude Xcode is broken.

Answer 1

I am fully aware that the problem is in the preprocessor.
I wouldn't call not being able to preprocess anything that does not have apple specific flags as working "fine". 
I had to switch to fink supplied compiler suite (which includes an alternative preprocessor) even for Quantum Espresso. It was compiling reasonably well with slighthly modified gcc settings before the update.
Last, but not the least, the aforementioned include file has nothing to do with fink.