[ConstraintSystem] Add Solution::getResolvedType to get a concrete type for a given ASTNode

Author: xedin

lib/Sema/CSApply.cpp

@@ -8415,6 +8415,10 @@ Type Solution::getType(ASTNode node) const {
   return cs.getType(node);
 }
 
+Type Solution::getResolvedType(ASTNode node) const {
+  return simplifyType(getType(node));
+}
+
 void Solution::setExprTypes(Expr *expr) const {
   if (!expr)
     return;

lib/Sema/ConstraintSystem.h

@@ -1190,6 +1190,11 @@ class Solution {
   /// Retrieve the type of the given node, as recorded in this solution.
   Type getType(ASTNode node) const;
 
+  /// Retrieve the type of the given node as recorded in this solution
+  /// and resolve all of the type variables in contains to form a fully
+  /// "resolved" concrete type.
+  Type getResolvedType(ASTNode node) const;
+
   /// Resolve type variables present in the raw type, using generic parameter
   /// types where possible.
   Type resolveInterfaceType(Type type) const;