Add a testcase for r184074.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184080 91177308-0d34-0410-b5e6-96231b3b80d8

test/Other/Inputs/TestProg/TestProg

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+false

test/Other/can-execute.txt

@@ -0,0 +1,20 @@
+REQUIRES: shell
+
+This tests that we abstract two peculiarities of unix in can_execute:
+
+* Directories are executable, but we don't want to try to execute them.
+* For shell scripts, we also need to be able to read them.
+
+The PATH is constructed such that 'not' will first find a directory named
+TestProg, then a file with executable bit but not readable and finally a
+shell script which always returns false, which is what it actually tries to
+execute.
+
+If we want, it is probably OK to change the semantics of can_execute and this
+test, but for now this test serves as a reminder to audit all the callers if
+we do that.
+
+RUN: cp -f %S/Inputs/TestProg/TestProg %T/TestProg
+RUN: chmod 111 %T/TestProg
+RUN: export PATH=%S/Inputs:%T:%S/Inputs/TestProg:$PATH
+RUN: not TestProg