remove a no-warn directive from GHC.Cmm.ContFlowOpt

This patch is motivated by the desire to remove the {-# OPTIONS_GHC
-fno-warn-incomplete-patterns #-} directive at the top of
GHC.Cmm.ContFlowOpt. (Based on the text in this coding standards doc, I
understand it's a goal of the project to remove such directives.) I
chose this task because I'm a new contributor to GHC, and it seemed like
a good way to get acquainted with the patching process.

In order to address the warning that arose when I removed the no-warn
directive, I added a case to removeUnreachableBlocksProc to handle the
CmmData constructor. Clearly, since this partial function has not been
erroring out in the wild, its inputs are always in practice wrapped by
the CmmProc constructor. Therefore the CmmData case is handled by a
precise panic (which is an improvement over the partial pattern match
from before).

0 files changed, 0 insertions, 0 deletions