Merge r1529495 from trunk, omitted from the initial apr escape backport:

Include @EXEEXT@ in references to gen_test_char in autoconf-based
build in order to fix the build on Windows.

PR: 55628
Submitted by: Carlo Bramini <carlo.bramix libero.it>
Reviewed by: trawick


git-svn-id: https://svn.apache.org/repos/asf/apr/apr/branches/1.5.x@1536536 13f79535-47bb-0310-9956-ffa450edef68