[committed] coroutines, testsuite: Renumber two tests (NFC).

[Iain Sandoe]

Hi,
This fixes a nit in the numbering of tests that I spotted while working on open
PRs.

tested on x86_64-linux/darwin.

applied to master
thanks
Iain

Try to keep tests order by distinct number (and with a short descriptive name 
appended).
 
gcc/testsuite/

2020-04-05  Iain Sandoe  <i...@sandoe.co.uk>
    
        * g++.dg/coroutines/torture/co-await-14-template-traits.C: Rename...
        * g++.dg/coroutines/torture/co-await-16-template-traits.C: to this.
        * g++.dg/coroutines/torture/co-await-15-capture-comp-ref.C: Rename..
        * g++.dg/coroutines/torture/co-await-17-capture-comp-ref.C: to this.

diff --git 
a/gcc/testsuite/g++.dg/coroutines/torture/co-await-14-template-traits.C 
b/gcc/testsuite/g++.dg/coroutines/torture/co-await-16-template-traits.C
similarity index 100%
rename from 
gcc/testsuite/g++.dg/coroutines/torture/co-await-14-template-traits.C
rename to gcc/testsuite/g++.dg/coroutines/torture/co-await-16-template-traits.C
diff --git 
a/gcc/testsuite/g++.dg/coroutines/torture/co-await-15-capture-comp-ref.C 
b/gcc/testsuite/g++.dg/coroutines/torture/co-await-17-capture-comp-ref.C
similarity index 100%
rename from 
gcc/testsuite/g++.dg/coroutines/torture/co-await-15-capture-comp-ref.C
rename to gcc/testsuite/g++.dg/coroutines/torture/co-await-17-capture-comp-ref.C