delete all dead code

ruby/ql/lib/codeql/ruby/dataflow/internal/SsaImplCommon.qll

@@ -287,20 +287,6 @@ private module SsaDefReaches {
     )
   }
 
-  /**
-   * Holds if the SSA definition of `v` at `def` reaches uncertain SSA definition
-   * `redef` in the same basic block, without crossing another SSA definition of `v`.
-   */
-  predicate ssaDefReachesUncertainDefWithinBlock(
-    SourceVariable v, Definition def, UncertainWriteDefinition redef
-  ) {
-    exists(BasicBlock bb, int rnk, int i |
-      ssaDefReachesRank(bb, def, rnk, v) and
-      rnk = ssaRefRank(bb, i, v, SsaDef()) - 1 and
-      redef.definesAt(v, bb, i)
-    )
-  }
-
   /**
    * Same as `ssaRefRank()`, but restricted to a particular SSA definition `def`.
    */

ruby/ql/lib/codeql/ruby/frameworks/Files.qll

@@ -191,10 +191,6 @@ module IO {
 
   // "Direct" `IO` instances, i.e. cases where there is no more specific
   // subtype such as `File`
-  private class IOInstanceStrict extends IOInstance {
-    IOInstanceStrict() { this = ioInstance() }
-  }
-
   /**
    * A `DataFlow::CallNode` that reads data using the `IO` class. For example,
    * the `read` and `readline` calls in: