[WIP][wasm-reduce] Inital type reducer

Sharing now in case it's useful, but not yet ready for review.

Author: tlively

src/tools/wasm-reduce/CMakeLists.txt

@@ -2,6 +2,7 @@ FILE(GLOB wasm_reduce_HEADERS *h)
 set(wasm_reduce_SOURCES
   destructive-reducer.cpp
   reducer.cpp
+  type-reducer.cpp
   wasm-reduce.cpp
   ${wasm_reduce_HEADERS}
 )

src/tools/wasm-reduce/destructive-reducer.cpp

@@ -217,6 +217,8 @@ void DestructiveReducer::visitExpression(Expression* curr) {
         }
       }
     }
+  } else if (curr->is<RefEq>()) {
+    handleCondition(*getCurrentPointer());
   }
   // Finally, try to replace with a child.
   for (auto* child : ChildIterator(curr)) {

src/tools/wasm-reduce/reducer.cpp

@@ -19,6 +19,7 @@
 #include "support/file.h"
 #include "support/path.h"
 #include "support/timing.h"
+#include "tools/wasm-reduce/type-reducer.h"
 #include "wasm-io.h"
 
 namespace {
@@ -268,7 +269,9 @@ size_t Reducer::reduceDestructively(int factor) {
   // destroy!
   DestructiveReducer destructiveReducer(*this);
   destructiveReducer.walkModule(&wasm);
-  return destructiveReducer.reduced;
+
+  TypeReducer typeReducer(*this);
+  return destructiveReducer.reduced + typeReducer.reduce();
 }
 
 bool Reducer::writeAndTestReduction() {