[libomptarget][amdgcn] Drop use of inttypes.h, moving closer to freestanding

[JonChesterfield]

Summary

[libomptarget][amdgcn] Drop use of inttypes.h, moving closer to freestanding

The glibc headers are a periodic source of problems compiling the devicertl.
This patch resolves the following error run into while building llvm on a slightly
different linux system.

In file included from .../lib/clang/13.0.0/include/inttypes.h:21:
In file included from /usr/include/inttypes.h:25:
/usr/include/features.h:461:12: fatal error: 'sys/cdefs.h' file not found
#  include <sys/cdefs.h>
           ^~~~~~~~~~~~~

As a second patch, removing assert.h from shuffle will let amdgcn build as
-ffreestanding, at which point only the headers that clang itself provides are
used and interactions with the host glibc are eliminated. Doing the same for
nvptx is complicated by printf handling but also seems worthwhile.

[JonChesterfield]

openmp/libomptarget/deviceRTLs/amdgcn/src/target_impl.h

24

Could equally remove the handful of uses of these macros, but this seems fine. The target_impl header is internal to the library.

openmp/libomptarget/deviceRTLs/common/include/target/shuffle.h

19

This didn't use stuff from inttypes specifically, stdint suffices

[tianshilei1992]

LGTM.

openmp/libomptarget/deviceRTLs/amdgcn/src/target_impl.h

 #define OMPTARGET_AMDGCN_TARGET_IMPL_H
 
 #ifndef __AMDGCN__
 #error "amdgcn target_impl.h expects to be compiled under __AMDGCN__"
 #endif
 
 #include "amdgcn_interface.h"
 
-#include <inttypes.h>
 #include <stddef.h>
 #include <stdint.h>
 
+// subset of inttypes.h
+#define PRId64 "ld"
+#define PRIu64 "lu"
+
 #define DEVICE
 #define INLINE inline DEVICE
 #define NOINLINE __attribute__((noinline)) DEVICE
 #define ALIGN(N) __attribute__((aligned(N)))
 
 ////////////////////////////////////////////////////////////////////////////////
 // Kernel options
 ////////////////////////////////////////////////////////////////////////////////

openmp/libomptarget/deviceRTLs/common/include/target/shuffle.h

 // Note: We unify the mask type to uint64_t instead of __kmpc_impl_lanemask_t.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LIBOMPTARGET_DEVICERTL_SHUFFLE_H
 #define LIBOMPTARGET_DEVICERTL_SHUFFLE_H
 
 #include <assert.h>
-#include <inttypes.h>
+#include <stdint.h>
 
 #pragma omp declare target
 
 /// External shuffle API
 ///
 ///{
 
 extern "C" {