* src/dir.c: Preserve glob d_type field

* src/dir.c: Preserve glob d_type field

When using GNU make on a system with glibc glob a pattern ending in
a slash is also matching regular files, but only in subdirectories:

$ mkdir -p dir/subdir
$ cd dir
$ touch file1 subdir/file2
$ echo 'test:; @echo $(wildcard */ */*/)' | make -f -
subdir/ subdir/file2
$ echo 'test: */ */*/; @echo "$?" != */ */*/' | make -f -
subdir/ subdir/file2 != subdir/ */*/

It happens because in the gl->gl_readdir callback supplied to glob(),
dirent->d_type is set to DT_UNKNOWN, and the glob() implementation
in glibc assumes that such a directory entry *cannot* possibly be a
regular file.

Pass the actual d_type down to glob(); this is the right thing to do
even if glibc is fixed, because it saves an extra stat() syscall for
each dirent.

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