[PATCH] install-sh: Handle .exe extensions, for Cygwin portability

Hi,

You'll find below a suggestion of patch we've been using since 2002 with 
INN (a news server).
   https://inn.eyrie.org/trac/changeset/5703

-- 
Julien ÉLIE



Make install-sh properly handle .exe extensions.
Path from Greg Andruk.

* lib/install-sh: Handle .exe extensions, for Cygwin portability

--- install-sh.orig	2018-03-17 14:18:08.701045461 +0100
+++ install-sh.cygwin	2018-03-17 14:28:26.577421082 +0100
@@ -250,6 +250,11 @@
      -* | [=\(\)!]) src=./$src;;
    esac

+  # For Cygwin compatibility.
+  if [ -x "$src".exe ]; then
+    src=${src}.exe
+  fi
+
    if test -n "$dir_arg"; then
      dst=$src
      dstdir=$dst