[orc-rt] Remove (effectively) unused header orc-rt-c/orc-rt.h. NFCI.

This header was a placeholder in the initial project check-in, but is not used.
Time to remove it.

orc-rt/include/orc-rt-c/orc-rt.h

@@ -1,32 +0,0 @@
-//===- orc-rt-c/orc-rt.h - Placeholder header for orc-rt ----------*- C -*-===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-//
-// Placeholder header for initial orc-rt checkin.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef ORC_RT_C_ORC_RT_H
-#define ORC_RT_C_ORC_RT_H
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/// \addtogroup orc_rt_c_api orc-rt C APIs
-/// @{
-
-void orc_rt(void);
-
-/// @}
-///
-
-#ifdef __cplusplus
-} // extern "C"
-#endif
-
-#endif // ORC_RT_C_ORC_RT_H

orc-rt/lib/executor/CMakeLists.txt

@@ -1,5 +1,4 @@
 set(files
-  orc-rt-executor.cpp
   AllocAction.cpp
   ResourceManager.cpp
   RTTI.cpp

orc-rt/lib/executor/orc-rt-executor.cpp

@@ -1,15 +0,0 @@
-//===- orc-rt-executor.cpp - Placeholder implementation for orc-rt --------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-//
-// Placeholder implementation file for initial orc-rt checkin.
-//
-//===----------------------------------------------------------------------===//
-
-#include <stdio.h>
-
-extern "C" void orc_rt(void) { printf("hello, world!\n"); }

orc-rt/tools/orc-executor/orc-executor.cpp

@@ -10,9 +10,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "orc-rt-c/orc-rt.h"
-
 int main(int argc, char *argv[]) {
-  orc_rt();
   return 0;
 }