[Constraint system] Finish allowing one to record pattern types.

Author: DougGregor

lib/Sema/ConstraintSystem.h

@@ -1481,6 +1481,7 @@ class ConstraintSystem {
   llvm::DenseMap<const Expr *, TypeBase *> ExprTypes;
   llvm::DenseMap<const TypeLoc *, TypeBase *> TypeLocTypes;
   llvm::DenseMap<const VarDecl *, TypeBase *> VarTypes;
+  llvm::DenseMap<const Pattern *, TypeBase *> PatternTypes;
   llvm::DenseMap<std::pair<const KeyPathExpr *, unsigned>, TypeBase *>
       KeyPathComponentTypes;
 
@@ -2235,9 +2236,11 @@ class ConstraintSystem {
       ExprTypes[expr] = type.getPointer();
     } else if (auto typeLoc = node.dyn_cast<const TypeLoc *>()) {
       TypeLocTypes[typeLoc] = type.getPointer();
-    } else {
-      auto var = node.get<const VarDecl *>();
+    } else if (auto var = node.dyn_cast<const VarDecl *>()) {
       VarTypes[var] = type.getPointer();
+    } else {
+      auto pattern = node.get<const Pattern *>();
+      PatternTypes[pattern] = type.getPointer();
     }
 
     // Record the fact that we ascribed a type to this node.
@@ -2258,9 +2261,11 @@ class ConstraintSystem {
       ExprTypes.erase(expr);
     } else if (auto typeLoc = node.dyn_cast<const TypeLoc *>()) {
       TypeLocTypes.erase(typeLoc);
-    } else {
-      auto var = node.get<const VarDecl *>();
+    } else if (auto var = node.dyn_cast<const VarDecl *>()) {
       VarTypes.erase(var);
+    } else {
+      auto pattern = node.get<const Pattern *>();
+      PatternTypes.erase(pattern);
     }
   }
 
@@ -2287,9 +2292,11 @@ class ConstraintSystem {
       return ExprTypes.find(expr) != ExprTypes.end();
     } else if (auto typeLoc = node.dyn_cast<const TypeLoc *>()) {
       return TypeLocTypes.find(typeLoc) != TypeLocTypes.end();
-    } else {
-      auto var = node.get<const VarDecl *>();
+    } else if (auto var = node.dyn_cast<const VarDecl *>()) {
       return VarTypes.find(var) != VarTypes.end();
+    } else {
+      auto pattern = node.get<const Pattern *>();
+      return PatternTypes.find(pattern) != PatternTypes.end();
     }
   }