Transforms: re-check error handling for nested functions as well (#12950)

Since both in-tree AST transforms (playground and program counter) add
new ApplyExprs (and literals that turn into ApplyExprs), we need to
recheck nested function bodies as well as top-level ones.

rdar://problem/28784059

Author: jrose-apple

Diff for: lib/Sema/PCMacro.cpp

@@ -300,15 +300,12 @@ class Instrumenter : InstrumenterBase {
           EndLoc = FD->getParameterLists().back()->getSourceRange().End;
         }
 
-        if (EndLoc.isValid()) {
-          BraceStmt *NNB = prependLoggerCall(NB, {StartLoc, EndLoc});
-          if (NNB != B) {
-            FD->setBody(NNB);
-          }
-        } else {
-          if (NB != B) {
-            FD->setBody(NB);
-          }
+        if (EndLoc.isValid())
+          NB = prependLoggerCall(NB, {StartLoc, EndLoc});
+
+        if (NB != B) {
+          FD->setBody(NB);
+          TypeChecker(Context).checkFunctionErrorHandling(FD);
         }
       }
     } else if (auto *NTD = dyn_cast<NominalTypeDecl>(D)) {
@@ -675,12 +672,7 @@ void swift::performPCMacro(SourceFile &SF, TopLevelContext &TLC) {
           if (FD->getBody()) {
             ASTContext &ctx = FD->getASTContext();
             Instrumenter I(ctx, FD, TmpNameIndex);
-            Decl *NewDecl = I.transformDecl(FD);
-            if (AbstractFunctionDecl *NFD =
-                    dyn_cast<AbstractFunctionDecl>(NewDecl)) {
-              TypeChecker TC(ctx);
-              TC.checkFunctionErrorHandling(NFD);
-            }
+            I.transformDecl(FD);
             return false;
           }
         }

Diff for: lib/Sema/PlaygroundTransform.cpp

@@ -264,6 +264,7 @@ class Instrumenter : InstrumenterBase {
         BraceStmt *NB = transformBraceStmt(B);
         if (NB != B) {
           FD->setBody(NB);
+          TypeChecker(Context).checkFunctionErrorHandling(FD);
         }
       }
     } else if (auto *NTD = dyn_cast<NominalTypeDecl>(D)) {

Diff for: test/PlaygroundTransform/nested_function.swift

@@ -0,0 +1,54 @@
+// RUN: %empty-directory(%t)
+// RUN: cp %s %t/main.swift
+// RUN: %target-build-swift -Xfrontend -playground -Xfrontend -debugger-support -o %t/main %S/Inputs/PlaygroundsRuntime.swift %t/main.swift
+// RUN: %target-run %t/main | %FileCheck %s
+// RUN: %target-build-swift -Xfrontend -pc-macro -Xfrontend -playground -Xfrontend -debugger-support -o %t/main %S/Inputs/PlaygroundsRuntime.swift %S/Inputs/SilentPCMacroRuntime.swift %t/main.swift
+// RUN: %target-run %t/main | %FileCheck %s
+// REQUIRES: executable_test
+
+func returnSum() -> Int {
+  var y = 10
+  func add() {
+    y += 5
+  }
+  add()
+  let addAgain = {
+    y += 5
+  }
+  addAgain()
+  let addMulti = {
+    y += 5
+    _ = 0 // force a multi-statement closure
+  }
+  addMulti()
+  return y
+}
+
+returnSum()
+
+// CHECK-NOT: $builtin
+// CHECK: [9:{{.*}}] $builtin_log_scope_entry
+// CHECK-NEXT: [10:{{.*}}] $builtin_log[y='10']
+// CHECK-NEXT: [11:{{.*}}] $builtin_log_scope_entry
+// CHECK-NEXT: [12:{{.*}}] $builtin_log[y='15']
+// CHECK-NEXT: [11:{{.*}}] $builtin_log_scope_exit
+// CHECK-NEXT: [15:{{.*}}] $builtin_log[addAgain='{{.*}}']
+// CHECK-NEXT: [15:{{.*}}] $builtin_log_scope_entry
+
+// FIXME: We drop the log for the addition here.
+// CHECK-NEXT: [16:{{.*}}] $builtin_log[='()']
+
+// CHECK-NEXT: [15:{{.*}}] $builtin_log_scope_exit
+
+// FIXME: There's an extra, unbalanced scope exit here.
+// CHECK-NEXT: [9:{{.*}}] $builtin_log_scope_exit
+
+// CHECK-NEXT: [19:{{.*}}] $builtin_log[addMulti='{{.*}}']
+// CHECK-NEXT: [19:{{.*}}] $builtin_log_scope_entry
+// CHECK-NEXT: [20:{{.*}}] $builtin_log[y='25']
+// CHECK-NEXT: [21:{{.*}}] $builtin_log[='0']
+// CHECK-NEXT: [19:{{.*}}] $builtin_log_scope_exit
+// CHECK-NEXT: [24:{{.*}}] $builtin_log[='25']
+// CHECK-NEXT: [9:{{.*}}] $builtin_log_scope_exit
+// CHECK-NEXT: [27:{{.*}}] $builtin_log[='25']
+// CHECK-NOT: $builtin