ruby: also insert capturedExitRead-nodes by exceptional exits

Author: yoff

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

@@ -106,7 +106,6 @@ private predicate writesCapturedVariable(Cfg::BasicBlock bb, LocalVariable v) {
  * at index `i` in exit block `bb`.
  */
 private predicate capturedExitRead(Cfg::AnnotatedExitBasicBlock bb, int i, LocalVariable v) {
-  bb.isNormal() and
   writesCapturedVariable(bb.getAPredecessor*(), v) and
   i = bb.length()
 }

ruby/ql/test/query-tests/variables/DeadStoreOfLocal/DeadStoreOfLocal.expected

@@ -1,2 +1 @@
 | DeadStoreOfLocal.rb:2:5:2:5 | y | This assignment to $@ is useless, since its value is never read. | DeadStoreOfLocal.rb:2:5:2:5 | y | y |
-| DeadStoreOfLocal.rb:61:17:61:17 | x | This assignment to $@ is useless, since its value is never read. | DeadStoreOfLocal.rb:56:17:56:17 | x | x |

ruby/ql/test/query-tests/variables/DeadStoreOfLocal/DeadStoreOfLocal.rb

@@ -58,7 +58,7 @@ def get_retried x
         print x
         if x < 1
             begin
-                x += 1  #$ SPURIOUS: Alert
+                x += 1  #$ OK - the block may be executed again
                 raise StandardError
             end
         end