Define CORERT for ProjectN builds

CoreRT is component of ProjectN (aka .NET Native for UWP), but our current defines do not reflect it because of CORERT is not defined in ProjectN builds. This creates confusion for folks outside the core runtime team, and conflicts with our documentation. For example, https://github.com/dotnet/corert/blob/master/Documentation/intro-to-corert.md says "CoreRT is the .NET Core runtime that is optimized for AOT scenarios, which .NET Native targets". It does not say "CoreRT is the .NET Core runtime optimized for AOT scenarios that uses RyuJIT backend" or anything like that.

- Before this change:
     PROJECTN: defined in closed source ProjectN builds
     CORERT: defined in open source CoreRT builds
     CORECLR: defined in CoreCLR builds

- After this change:
     PROJECTN: defined in closed source ProjectN builds (same)
     CORERT: defined in both open source CoreRT builds and closed source ProjectN builds (different)
     CORECLR: defined in CoreCLR builds (same)

[tfs-changeset: 1680901]

1 files changed, 4 insertions, 4 deletions

diff --git a/src/Native/Runtime/windows/PalRedhawkMinWin.cpp b/src/Native/Runtime/windows/PalRedhawkMinWin.cpp
index c70ab884e..209b5c0b9 100644
--- a/src/Native/Runtime/windows/PalRedhawkMinWin.cpp
+++ b/src/Native/Runtime/windows/PalRedhawkMinWin.cpp
@@ -17,7 +17,7 @@
 #include <stdio.h>
 #include <errno.h>
 #include <evntprov.h>
-#ifndef CORERT
+#ifdef PROJECTN
 #include <roapi.h>
 #endif
 
@@ -1377,7 +1377,7 @@ REDHAWK_PALEXPORT _Ret_maybenull_ void* REDHAWK_PALAPI PalSetWerDataBuffer(_In_
 
 static LARGE_INTEGER g_performanceFrequency;
 
-#ifndef CORERT
+#ifdef PROJECTN
 static bool g_roInitialized;
 #endif
 
@@ -1391,7 +1391,7 @@ bool GCToOSInterface::Initialize()
         return false;
     }
 
-#ifndef CORERT
+#ifdef PROJECTN
     // TODO: Remove the RoInitialize call when we implement non-WinRT framework for classic apps
     HRESULT hr = RoInitialize(RO_INIT_MULTITHREADED);
 
@@ -1415,7 +1415,7 @@ bool GCToOSInterface::Initialize()
 //  Must be called on the same thread as Initialize.
 void GCToOSInterface::Shutdown()
 {
-#ifndef CORERT
+#ifdef PROJECTN
     if (g_roInitialized)
     {
         RoUninitialize();