[Libomptarget] Fix compiling with asserts using the bitcode library

[jhuber6]

Summary

Sumnmary:
A previous patch introduces an exports file which contains all the
symbol names that are not internalized in the bitcode library. This is
done to reduce the size of the bitcode library and only export needed
functions. This export file must contain all the functoins expected to
be called from the device. Since its introduction the __assert_fail
function used to be provided but was mistakenly not included. This patch
adds it.

Fixes #57656

[jdoerfert]

LG

[JonChesterfield]

It seems a bit sketchy to be defining libc symbols in the openmp runtime. Is there a reason we can't prefix these __omp or similar?

[jhuber6]

In D133594#3781111, @JonChesterfield wrote:

It seems a bit sketchy to be defining libc symbols in the openmp runtime. Is there a reason we can't prefix these __omp or similar?

Because assert is expanded to __assert_fail by the preprocessor, so we just provide that function.

openmp/libomptarget/DeviceRTL/src/exports

 omp_*
 *llvm_*
 __kmpc_*
 
 memcmp
 printf
+__assert_fail

openmp/libomptarget/test/api/assert.c

+// RUN: %libomptarget-compile-run-and-check-generic
+
+#include <assert.h>
+#include <stdio.h>
+
+int main() {
+  int i = 1;
+#pragma omp target
+  assert(i > 0);
+
+  // CHECK: PASS
+  printf("PASS\n");
+  return 0;
+}