I think lots of this checks are not necessary. Most of variables we define here are never used in the code. There is a list of used HAVE_* symbols:
```
HAVE_CONFIG_H
HAVE_FUSE_VERSION
HAVE_GETCWD
HAVE_GETPWUID
HAVE_GETRUSAGE
HAVE_MLOCKALL
HAVE_PERROR
HAVE_PREAD
HAVE_PWD_H
HAVE_PWRITE
HAVE_SETITIMER
HAVE_STRERROR_R
HAVE_STRUCT_RUSAGE_RU_MAXRSS
HAVE_STRUCT_STAT_ST_BIRTHTIME
HAVE_STRUCT_STAT_ST_BLKSIZE
HAVE_STRUCT_STAT_ST_BLOCKS
HAVE_STRUCT_STAT_ST_RDEV
HAVE_STRUCT_TM_TM_GMTOFF
HAVE_SYS_MMAN_H
HAVE_SYS_RESOURCE_H
HAVE_SYS_RUSAGE_H
HAVE_WRITEV
HAVE_ZLIB_H
```

This checks take a lot of time. I think we should put here only the interesting ones.