test, add regressions for Batch only empty message rendering

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
fix, PEBKAC, upon mremap() in resz_rndr() make sure the buffer size will be adapted

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, turn off downsizing of rndr buffers, instead pass on alloc size in slot z

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
fix, PEBKAC, provide proper result to compare fixml documents to, ...

The reference string didn't include the xml PI.

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, widen the initial buffer size in fixc_render_fixml_rndr() so that an empty Batch message would fit

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
fix, PEBKAC^2, explicitly mention newlines in reference string literal

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, lose local copy of p/ep pair in fixc_render_fixml_rndr() and use ctx.{p,ep} instead

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'core/render-fixml' into next

* core/render-fixml:
  minor, lose local copy of p/ep pair in fixc_render_fixml_rndr() and use ctx.{p,ep} instead
  fix, PEBKAC^2, explicitly mention newlines in reference string literal
  minor, widen the initial buffer size in fixc_render_fixml_rndr() so that an empty Batch message would fit
  fix, PEBKAC, provide proper result to compare fixml documents to, ...
  minor, turn off downsizing of rndr buffers, instead pass on alloc size in slot z
  fix, PEBKAC, upon mremap() in resz_rndr() make sure the buffer size will be adapted
  test, add regressions for Batch only empty message rendering