Haddock options should be concatenated

Currently we have the following situation:

1. If we have an OPTIONS_HADDOCK pragma, any CLI options from -haddock-opts are ignored
2. If there are multiple OPTIONS_HADDOCK pragmas, only the last one is remembered.

Instead all options should be concatenated (with , ), with the CLI options at the end.

Trac metadata

Trac field	Value
Version	8.5
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC	alexbiehl, hvr
Operating system
Architecture

changed milestone to %8.8.1

changed weight to 5

added Tbug Trac import labels

Sounds reasonable to me. Do you intend on fixing this, sjakobi?

As no-one seems to have run into this problem so far, I probably won't get to it before the end of August.

changed title from Haddock options should be concatened to Haddock options should be concatenated

changed milestone to %8.10.1

Bumping milestones of low-priority tickets.

added haddock label

added Pnormal label

removed milestone