Build for iOS (device) fails due to no crt_extern

[nsands]

Building GDAL 1.10 for iOS (device) fails due to no crt_extern on iOS. Note that it builds OK for the iOS simulator, but not for the device. The build error is included below, but the following fixed this error. In file 'cpl_spawn.cpp' Replace:

#ifdef __APPLE__
#include <crt_externs.h>

With:

#ifdef __APPLE__
# include <TargetConditionals.h>
#endif
#if defined(__APPLE__) && !defined(TARGET_OS_IPHONE)
#include <crt_externs.h>

For completeness, the error output before this change was:

libtool: compile: /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Dev eloper/usr/bin/g++ -arch armv7 -pipe -Os -gdwarf-2 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Dev eloper/SDKs/iPhoneOS6.1.sdk -mno-thumb -mthumb-interwork -Wall -DOGR_ENABLED -I/Users/nsands/Documents/Nik/Development/gdal-1.10.0/port -DHAVE_LIBZ -I/usr/include/libxml2 -DHAVE_LIBXML2 -c cpl_spawn.cpp -o cpl_spawn.o cpl_spawn.cpp:465:25: error: crt_externs.h: No such file or directory cpl_spawn.cpp: In function 'CPLSpawnedProcess* CPLSpawnAsync(int (*)(CPL_FILE_HANDLE, CPL_FILE_HANDLE), const char* const*, int, int, int, char)': cpl_spawn.cpp:727: error: '_NSGetEnviron' was not declared in this scope make[1]: * [cpl_spawn.lo] Error 1 make: * [port-target] Error 2