fix realpath.mk add wildcard_cache.mk

info.make "Reading Makefiles" says

Rule Definition
---------------

A rule is always expanded the same way, regardless of the form:

     IMMEDIATE : IMMEDIATE ; DEFERRED
        DEFERRED

   That is, the target and prerequisite sections are expanded
immediately, and the commands used to construct the target are always
deferred.  This general rule is true for explicit rules, pattern rules,
suffix rules, static pattern rules, and simple prerequisite definitions.

so, cmds evaluation should be deferred.

however, I found strange case in wildcard usage.
see wildcard_cache.mk
6 files changed