[ClosureExpr] Remove hasAppliedFunctionBuilder.

There are no longer any clients of the "has applied function builder" bit
in ClosureExpr, so remove it.

Author: DougGregor

include/swift/AST/Expr.h

@@ -3770,10 +3770,7 @@ class ClosureExpr : public AbstractClosureExpr {
   /// the CaptureListExpr which would normally maintain this sort of
   /// information about captured variables), we need to have some way to access
   /// this information directly on the ClosureExpr.
-  ///
-  /// The bit indicates whether this closure has had a function builder
-  /// applied to it.
-  llvm::PointerIntPair<VarDecl *, 1, bool> CapturedSelfDeclAndAppliedBuilder;
+  VarDecl * CapturedSelfDecl;
 
   /// The location of the "throws", if present.
   SourceLoc ThrowsLoc;
@@ -3800,7 +3797,7 @@ class ClosureExpr : public AbstractClosureExpr {
     : AbstractClosureExpr(ExprKind::Closure, Type(), /*Implicit=*/false,
                           discriminator, parent),
       BracketRange(bracketRange),
-      CapturedSelfDeclAndAppliedBuilder(capturedSelfDecl, false),
+      CapturedSelfDecl(capturedSelfDecl),
       ThrowsLoc(throwsLoc), ArrowLoc(arrowLoc), InLoc(inLoc),
       ExplicitResultTypeAndEnclosingChecked(explicitResultType, false),
       Body(nullptr) {
@@ -3906,22 +3903,14 @@ class ClosureExpr : public AbstractClosureExpr {
 
   /// VarDecl captured by this closure under the literal name \c self , if any.
   VarDecl *getCapturedSelfDecl() const {
-    return CapturedSelfDeclAndAppliedBuilder.getPointer();
+    return CapturedSelfDecl;
   }
 
   /// Whether this closure captures the \c self param in its body in such a
   /// way that implicit \c self is enabled within its body (i.e. \c self is
   /// captured non-weakly).
   bool capturesSelfEnablingImplictSelf() const;
 
-  bool hasAppliedFunctionBuilder() const {
-    return CapturedSelfDeclAndAppliedBuilder.getInt();
-  }
-
-  void setAppliedFunctionBuilder(bool flag = true) {
-    CapturedSelfDeclAndAppliedBuilder.setInt(flag);
-  }
-
   /// Whether this closure's body was type checked within the enclosing
   /// context.
   bool wasTypeCheckedInEnclosingContext() const {

lib/Sema/CSClosure.cpp

@@ -333,7 +333,6 @@ SolutionApplicationToFunctionResult ConstraintSystem::applySolution(
 
     fn.setBody(newBody, /*isSingleExpression=*/false);
     if (closure) {
-      closure->setAppliedFunctionBuilder();
       closure->setTypeCheckedInEnclosingContext();
       solution.setExprTypes(closure);
     }