run-tests: pre instantiate pygments objects...
run-tests: pre instantiate pygments objects
This speeds up run-tests.py diff output by 10x, which affects developer
experience significantly. As demonstrated by the following test:
```
#require pygments
$ for i in `seq 1 200`; do
> echo ' $ echo '$i >> test-a.t
> echo ' wrong' >> test-a.t
> done
$ cat > walltime.py <<EOF
> from __future__ import absolute_import, print_function
> import os, sys, time
> t1 = time.time()
> os.system(' '.join(sys.argv[1:]) + ' >/dev/null 2>/dev/null')
> t2 = time.time()
> print('%0.2f' % (t2 - t1))
> EOF
$ $PYTHON walltime.py $TESTDIR/run-tests.py -l --color=never $TESTTMP/test-a.t
0.24
Before this patch:
$ $PYTHON walltime.py $TESTDIR/run-tests.py -l --color=always $TESTTMP/test-a.t
2.46
After this patch:
$ $PYTHON walltime.py $TESTDIR/run-tests.py -l --color=always $TESTTMP/test-a.t
0.25
```
