Merge pull request #2364 from cdornan/regex

Add Chris Dornan's regex packages

build-constraints.yaml

@@ -2841,6 +2841,10 @@ packages:
     "Devon Hollowood <devonhollowood@gmail.com> @devonhollowood":
         - search-algorithms
 
+    "Chris Dornan <chris@chrisdornan.com> @cdornan":
+        - regex
+        - regex-examples
+
     # If you stop maintaining a package you can move it here.
     # It will then be disabled if it starts causing problems.
     # See https://github.com/fpco/stackage/issues/1056