perf tools: Makefile: Remove platform-specific cruft

perf tools: Makefile: Remove platform-specific cruft

While it makes sense that this tool could be used on
other platforms at least to parse data, there doesn't
appear to be any real support for such usage.

This commit squashes several commits that remove:

 SNPRINTF_RETURNS_BOGUS
 FREAD_READS_DIRECTORIES
 NO_D_{INO,TYPE}_IN_DIRENT
 NO_STRCASESTR
 NO_MEMMEM
 NO_STRTOUMAX and NO_STRTOULL
 NO_SETENV
 NO_UNSETENV
 NO_MKDTEMP
 NEEDS_LIBICONV
 NEEDS_SOCKET
 NO_MMAP
 NO_PTHREADS
 NO_PREAD
 NO_TRUSTABLE_FILEMODE
 NO_IPV6 and NO_SOCKADDR_STORAGE
 NO_ICONV and OLD_ICONV
 NO_NSEC, USE_NSEC, and USE_ST_TIMESPEC
 NO_ST_BLOCKS_IN_STRUCT_STAT
 NO_FINK and NO_DARWIN_PORTS
 NO_SYS_SELECT_H
 NO_HSTRERROR
 DIR_HAS_BSD_GROUP_SEMANTICS and FORCE_DIR_SET_GID
 NEEDS_NSL, NO_UINTMAX_T, NO_INET_{N,P}TON
 COMPAT_{CFLAGS,OBJS}
 Executable extension `X'

Signed-off-by: Michael Witten <mfwitten@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>