[csmith-project/creduce] a7d703: Use envvars to select Clang and GCC for tests.

[Eric Eide <eeide@cs.utah.edu>]

  Branch: refs/heads/master
  Home:   https://github.com/csmith-project/creduce
  Commit: a7d703ab94fd0733a0ad126abd269a14da9f30f1
      https://github.com/csmith-project/creduce/commit/a7d703ab94fd0733a0ad126abd269a14da9f30f1
  Author: Eric Eide <eeide@cs.utah.edu>
  Date:   2016-05-11 (Wed, 11 May 2016)

  Changed paths:
    M tests/README
    M tests/test0.sh
    M tests/test1.sh
    M tests/test2.sh
    M tests/test3.sh
    M tests/test4.sh
    M tests/test5.sh
    M tests/test6.sh
    M tests/test7.sh

  Log Message:
  -----------
  Use envvars to select Clang and GCC for tests.

Consult the environment variables `CLANG` and `GCC` to find the Clang
and GCC binaries, respectively.  The defaults are "clang" and "gcc".

This commit is based on a patch submitted by Matthias Klose.  Thanks,
Matthias!