genTryCpp codegen. Fixes #7232. Fixes #7239 (#7240)

tests/cpp/tcppraise.nim

@@ -3,7 +3,9 @@ discard """
   output: '''foo
 bar
 Need odd and >= 3 digits##
-baz'''
+baz
+caught
+'''
 """
 
 # bug #1888
@@ -15,3 +17,21 @@ try:
 except ValueError:
   echo getCurrentExceptionMsg(), "##"
 echo "baz"
+
+
+# bug 7232
+try:
+ discard
+except KeyError, ValueError:
+  echo "except handler" # should not be invoked
+
+
+#bug 7239
+try:
+  try:
+    raise newException(ValueError, "asdf")
+  except KeyError, ValueError:
+    raise
+except:
+  echo "caught"
+