[OpenMP] Move header inclusion out of 'extern "C"'

This leads to problems when compiling C++ code with libc++ for Nvidia GPUs
because Clang now uses wrappers for math functions that might include
C++ templates not allowed in 'extern "C"'.

Differentiel Revision: https://reviews.llvm.org/D64625

git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@366229 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/runtime/src/include/omp.h.var b/runtime/src/include/omp.h.var
index 54ba1f5..2246e70 100644
--- a/runtime/src/include/omp.h.var
+++ b/runtime/src/include/omp.h.var
@@ -15,6 +15,9 @@
 #ifndef __OMP_H
 #   define __OMP_H
 
+#   include <stdlib.h>
+#   include <stdint.h>
+
 #   define KMP_VERSION_MAJOR    @LIBOMP_VERSION_MAJOR@
 #   define KMP_VERSION_MINOR    @LIBOMP_VERSION_MINOR@
 #   define KMP_VERSION_BUILD    @LIBOMP_VERSION_BUILD@
@@ -134,8 +137,6 @@
     extern int  __KAI_KMPC_CONVENTION  omp_get_team_num (void);
     extern int  __KAI_KMPC_CONVENTION  omp_get_cancellation (void);
 
-#   include <stdlib.h>
-#   include <stdint.h>
     /* OpenMP 4.5 */
     extern int   __KAI_KMPC_CONVENTION  omp_get_initial_device (void);
     extern void* __KAI_KMPC_CONVENTION  omp_target_alloc(size_t, int);