1037 - #endif without matching #if.

Description
Every #endif directive must be preceeded by an accompanying #if directive.
Example
Config:
#if __WINDOWS__ #endif #endif
Output:
C:\Test\fbuild.bff(3,2): FASTBuild Error #1037 - #endif without matching #if. #endif ^ \--here
Fix:
#if __WINDOWS__ #endif #if __LINUX__ #endif