[PCMacro] Implemented support for defer statements in the PC macro.

As with the playground transform, defer statements were not supported in the PC macro.
This commit addresses that oversight.

This partially addresses <rdar://problem/29007242>.

(cherry picked from commit 2c04058)

Author: cwakamo

lib/Sema/PCMacro.cpp

@@ -52,6 +52,8 @@ class Instrumenter : InstrumenterBase {
       return S;
     case StmtKind::Brace:
       return transformBraceStmt(cast<BraceStmt>(S));
+    case StmtKind::Defer:
+      return transformDeferStmt(cast<DeferStmt>(S));
     case StmtKind::If:
       return transformIfStmt(cast<IfStmt>(S));
     case StmtKind::Guard:
@@ -282,6 +284,18 @@ class Instrumenter : InstrumenterBase {
     }
     return DCS;
   }
+  
+  DeferStmt *transformDeferStmt(DeferStmt *DS) {
+    if (auto *FD = DS->getTempDecl()) {
+      auto Implicit = FD->isImplicit();
+      FD->setImplicit(false);
+      auto *D = transformDecl(FD);
+      D->setImplicit(Implicit);
+      assert(D == FD);
+    }
+    return DS;
+
+  }
 
   Decl *transformDecl(Decl *D) {
     if (D->isImplicit())

test/PCMacro/defer.swift

@@ -0,0 +1,30 @@
+// RUN: rm -rf %t
+// RUN: mkdir -p %t
+// RUN: cp %s %t/main.swift
+// RUN: %target-build-swift -Xfrontend -pc-macro -o %t/main %S/Inputs/PCMacroRuntime.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/PCMacroRuntime.swift %t/main.swift %S/Inputs/SilentPlaygroundsRuntime.swift
+// RUN: %target-run %t/main | %FileCheck %s
+// REQUIRES: executable_test
+
+// FIXME: rdar://problem/30234450 PCMacro tests fail on linux in optimized mode
+// UNSUPPORTED: OS=linux-gnu
+
+#sourceLocation(file: "main.swift", line: 8)
+func foo() {
+  defer {
+    2
+  }
+  1
+}
+
+foo()
+
+// CHECK: [15:1-15:6] pc before
+// CHECK-NEXT: [8:1-8:11] pc before
+// CHECK-NEXT: [8:1-8:11] pc after
+// CHECK-NEXT: [12:3-12:4] pc before
+// CHECK-NEXT: [12:3-12:4] pc after
+// CHECK-NEXT: [10:5-10:6] pc before
+// CHECK-NEXT: [10:5-10:6] pc after
+// CHECK-NEXT: [15:1-15:6] pc after