Fix CodeQL query warnings and errors

non-javadoc-block-comment.ql now uses raw HTML in the QLDoc. The Query Console
seems to support it, but the VSCode extension does not, see
github/vscode-codeql#794.
Could also omit the closing `*/` from the QLDoc in the future, if necessary.

Author: Marcono1234

codeql-custom-queries-java/queries/javadoc/non-javadoc-block-comment.ql

@@ -1,6 +1,6 @@
 /**
- * Finds regular block comments (`/* ... */`) which appear to be meant to
- * be javadoc comments (`/** ... */`).
+ * Finds regular block comments (<code>/* ... &ast;/</code>) which appear to be meant to
+ * be javadoc comments (<code>/** ... &ast;/</code>).
  *
  * Note that this (on purpose) matches comments which start with `/* (non-Javadoc)`.
  * These comments are generated by some IDEs and add little value since IDEs usually

codeql-custom-queries-java/queries/unit-tests/test-not-failing-on-missing-exception.ql

@@ -59,7 +59,7 @@ predicate isFailMethodCall(MethodAccess call, Method m) {
     )
 }
 
-predicate isFailing(Block tryBlock) {
+predicate isFailing(BlockStmt tryBlock) {
     exists(MethodAccess failCall, ExprStmt failCallStmt |
         isFailMethodCall(failCall, failCall.getMethod())
         and failCall.getEnclosingStmt() = failCallStmt