Consistency of method names in BaseTypeVisitor

[wmdietl]

Methods that check some property and issue errors/warnings if the property are violated are usually called "check":

grep "void check" framework/src/main/java/org/checkerframework/common/basetype/BaseTypeVisitor.java
    protected void checkQualifierParameter(ClassTree classTree) {
    protected void checkExtendsAndImplements(ClassTree classTree) {
    protected void checkExtendsOrImplements(
    protected void checkFieldInvariantDeclarations(ClassTree classTree) {
    protected void checkDefaultConstructor(ClassTree tree) {}
    protected void checkPurityAnnotations(MethodTree tree) {
    protected void checkConstructorResult(
    private void checkContractsAtMethodDeclaration(
    private void checkParametersAreEffectivelyFinal(
    protected void checkPostcondition(
    protected void checkConditionalPostcondition(
    protected void checkExplicitAnnotationsOnIntersectionBounds(
    protected void checkThisConstructorCall(MethodInvocationTree thisCall) {
    protected void checkSuperConstructorCall(MethodInvocationTree superCall) {
    protected void checkThisOrSuperConstructorCall(
    protected void checkVarargs(AnnotatedExecutableType invokedMethod, Tree tree) {
    protected void checkPreconditions(MethodInvocationTree tree, Set<Precondition> preconditions) {
    protected void checkTypecastRedundancy(TypeCastTree typeCastTree) {
    protected void checkTypecastSafety(TypeCastTree typeCastTree) {
    protected void checkExceptionParameter(CatchTree tree) {
    protected void checkThrownExpression(ThrowTree tree) {
    protected void checkTypeArguments(
    private void checkHasQualifierParameterAsTypeArgument(
    protected void checkMethodInvocability(
    protected void checkConstructorInvocation(
    protected void checkEnclosingExpr(NewClassTree node, AnnotatedExecutableType constructorType) {
    protected void checkArguments(
        private void checkPurity() {
        private void checkPreAndPostConditions() {
        private void checkParametersMsg(
        private void checkReturnMsg(boolean success) {
    private void checkContractsSubset(
    protected void checkAccess(IdentifierTree identifierTree, Void p) {
    protected void checkAccessAllowed(

However, a few are called "warn":

> grep "void warn" framework/src/main/java/org/checkerframework/common/basetype/BaseTypeVisitor.java
    protected void warnInvalidPolymorphicQualifier(ClassTree classTree) {
    protected void warnInvalidPolymorphicQualifier(
    protected void warnRedundantAnnotations(Tree tree, AnnotatedTypeMirror type) {
    private void warnAboutTypeAnnotationsTooEarly(Tree tree, ModifiersTree modifiersTree) {
    public void warnAboutIrrelevantJavaTypes(

I noticed this because #1080 renamed checkForPolymorphicQualifiers to warnInvalidPolymorphicQualifier which seems inconsistent.

Think through what our guidance for method names should be, adapt the code, and document it in the class documentation and the developer guide.