There is no guarantee that Integer#size will continue to return
`sizeof(long)` for small integers.
Use the `l!` specifier for Array#pack instead. It is a public
interface that has a direct relationship with the `long` type.
What a "word" is when talking about sizes is confusing because it's a
highly overloaded term. Intel, Microsoft, and GDB are just a few vendors
that have their own definition of what a "word" is. Specs that used the
"wordsize" guard actually were mostly testing for the size of the C
`long` fundamental type, so rename the guard for clarity.
Also, get the size of `long` directly from RbConfig instead of guessing
using Integer#size. Integer#size is not guaranteed to have anything to
do with the `long` type.
```
1)
Dir.mktmpdir when passed a block yields the path to the passed block ERROR
ArgumentError: parent directory is world writable but not sticky: /tmp/rubytest.wlu5cs_11
/tmp/ruby/src/trunk/lib/tmpdir.rb:113:in 'Dir.mktmpdir'
/tmp/ruby/src/trunk/spec/ruby/library/tmpdir/dir/mktmpdir_spec.rb:39:in 'block (2 levels) in <top (required)>'
```
This weird error comes from world-writable (and not sticky) directory
of `SPEC_TEMP_DIR`.
This patch checks `SPEC_TEMP_DIR` is not world-writable if exists
and `File.umask` contains o+w mask.
The leakchecker will report leaked file descriptors when tests do things
like access `Etc.getgrgid`, for example, if NSS modules (like `sss`)
handle these lookups by connecting to a daemon like `sssd` and leave the
connection open.
To address this, we can call glibc's `__nss_configure_lookup` to
override NSS modules configured in /etc/nsswitch.conf and only use
ordinary file/DNS lookups.
(This is a cherry-pick of a patch applied to ruby/mspec here:
https://github.com/ruby/mspec/pull/62)
