git-am: use apply --cached
git-am: use apply --cached

Now 'git apply' can apply patch without working tree, preparation
of pristine preimage and postimage trees that are done when falling
back on 3-way merge by "git am" can do so without temporary files.

Signed-off-by: Junio C Hamano <dc50d1021234060e53ec42a77d526afa2fe07479@cox.net>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git