Speed up typetree operator[] (rust-lang#454)

* Speed up typetree operator[]

* Fix tests

* Speed up set and purge

* Speed up insert

* Remove extra clobber check

Author: wsmoses

enzyme/Enzyme/Enzyme.cpp

@@ -788,6 +788,7 @@ class Enzyme : public ModulePass {
         } else if (et->isPointerTy()) {
           dt = TypeTree(ConcreteType(BaseType::Pointer)).Only(-1);
         }
+        dt.insert({}, BaseType::Pointer);
       } else if (a.getType()->isIntOrIntVectorTy()) {
         dt = ConcreteType(BaseType::Integer);
       }

enzyme/Enzyme/TypeAnalysis/TypeAnalysisPrinter.cpp

@@ -93,6 +93,7 @@ class TypeAnalysisPrinter : public FunctionPass {
         } else if (et->isPointerTy()) {
           dt = TypeTree(ConcreteType(BaseType::Pointer)).Only(-1);
         }
+        dt.insert({}, BaseType::Pointer);
       } else if (a.getType()->isIntOrIntVectorTy()) {
         dt = ConcreteType(BaseType::Integer);
       }