mmaprototype: move unused constraint functions to _test.go file

They are being used from tests. Make this clearer by
making these functions available only in the test.
If we decide to actually use them in production,
they can be moved back.

Author: tbg

pkg/kv/kvserver/allocator/mmaprototype/BUILD.bazel

@@ -9,7 +9,6 @@ go_library(
         "cluster_state_rebalance_stores.go",
         "constraint.go",
         "constraint_matcher.go",
-        "constraint_unused.go",
         "doc.go",
         "load.go",
         "memo_helper.go",
@@ -44,6 +43,7 @@ go_test(
         "cluster_state_test.go",
         "constraint_matcher_test.go",
         "constraint_test.go",
+        "constraint_unused_test.go",
         "load_test.go",
         "memo_helper_test.go",
     ],

pkg/kv/kvserver/allocator/mmaprototype/constraint.go

@@ -1564,15 +1564,7 @@ func init() {
 	var _ = rac.stateForInit
 	var _ = rac.finishInit
 	var _ = rac.notEnoughVoters
-	var _ = rac.candidatesToConvertFromNonVoterToVoter
-	var _ = rac.constraintsForAddingVoter
 	var _ = rac.notEnoughNonVoters
-	var _ = rac.candidatesToConvertFromVoterToNonVoter
-	var _ = rac.constraintsForAddingNonVoter
-	var _ = rac.candidatesForRoleSwapForConstraints
-	var _ = rac.candidatesToRemove
-	var _ = rac.candidatesVoterConstraintsUnsatisfied
-	var _ = rac.candidatesNonVoterConstraintsUnsatisfied
 	var _ = rac.candidatesToReplaceVoterForRebalance
 	var _ = rac.candidatesToReplaceNonVoterForRebalance
 

pkg/kv/kvserver/allocator/mmaprototype/constraint_matcher.go

@@ -213,9 +213,3 @@ func (cm *constraintMatcher) constrainStoresForExpr(expr constraintsDisj, set *s
 		}
 	}
 }
-
-// Avoid unused lint errors.
-
-var _ = (&constraintMatcher{}).setStore
-var _ = (&constraintMatcher{}).removeStore
-var _ = (&constraintMatcher{}).checkConsistency