simplify mkSkolem naming system: don't use $$

Short summary: By default NODEID is appeneded, just continue doing what you
were, just don't add the _$$ at the end.

Long summary:

Before this commit there were four (yes!) ways to specify the names for new
skolems, which result in names as given below

1) mkSkolem("name", ..., SKOLEM_FLAG_DEFAULT)  -> "name_NODEID"
2) mkSkolem("name", ..., SKOLEM_EXACT_NAME)  -> "name"
3) mkSkolem("name_$$", ..., SKOLEM_FLAG_DEFAULT) -> "name_NODEID"
4) mkSkolem("na_$$_me", ..., SKOLEM_FLAG_DEFAULT) -> "na_NODEID_me"

After this commit, only 1) and 2) stay.

90% usage is of 1) or 3), which results in exact same behavior (and
looking at the source code it doesn't look like everyone realized that
the _$$ is just redundant).

Almost no one used 4), which is the only reason to even have $$. Post this
commit if you really want a number in the middle, manually construct the
name and use the SKOLEM_EXACT_NAME flag.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/theory/ite_utilities.cpp b/src/theory/ite_utilities.cpp
index a4af4f26f..35330f81a 100644
--- a/src/theory/ite_utilities.cpp
+++ b/src/theory/ite_utilities.cpp
@@ -307,7 +307,7 @@ Node ITECompressor::push_back_boolean(Node original, Node compressed){
     return rewritten;
   }else{
     NodeManager* nm = NodeManager::currentNM();
-    Node skolem = nm->mkSkolem("compress_$$", nm->booleanType());
+    Node skolem = nm->mkSkolem("compress", nm->booleanType());
     d_compressed[rewritten] = skolem;
     d_compressed[original] = skolem;
     d_compressed[compressed] = skolem;
@@ -1175,7 +1175,7 @@ Node ITESimplifier::getSimpVar(TypeNode t)
     return (*it).second;
   }
   else {
-    Node var = NodeManager::currentNM()->mkSkolem("iteSimp_$$", t, "is a variable resulting from ITE simplification");
+    Node var = NodeManager::currentNM()->mkSkolem("iteSimp", t, "is a variable resulting from ITE simplification");
     d_simpVars[t] = var;
     return var;
   }