[OpenMP] remove obsolete symbol defintions

Some globals were used for enforcing certain linking rules in the Intel
OpenMP implementation's MSVC compatibility layer and are not applicable
to the LLVM implementation (kmp_import.cpp has already been removed from
the build).

Differential Revision:https://reviews.llvm.org/D145837

openmp/runtime/src/dllexports

@@ -186,9 +186,6 @@
         __kmp_omp_debug_struct_info             DATA
     %endif
 
-    # Symbols for MS mutual detection:
-    _You_must_link_with_exactly_one_OpenMP_library    DATA
-    _You_must_link_with_Intel_OpenMP_library          DATA
     __kmp_wait_64
     __kmp_release_64
 

openmp/runtime/src/kmp.h

@@ -4184,13 +4184,6 @@ KMP_EXPORT void *__kmpc_threadprivate_cached(ident_t *loc, kmp_int32 global_tid,
                                              void *data, size_t size,
                                              void ***cache);
 
-// Symbols for MS mutual detection.
-extern int _You_must_link_with_exactly_one_OpenMP_library;
-extern int _You_must_link_with_Intel_OpenMP_library;
-#if KMP_OS_WINDOWS && (KMP_VERSION_MAJOR > 4)
-extern int _You_must_link_with_Microsoft_OpenMP_library;
-#endif
-
 // The routines below are not exported.
 // Consider making them 'static' in corresponding source files.
 void kmp_threadprivate_insert_private_data(int gtid, void *pc_addr,

openmp/runtime/src/kmp_global.cpp

@@ -547,13 +547,6 @@ int get_suspend_count_(void) {
 void set_suspend_count_(int *value) { __kmp_suspend_count = *value; }
 #endif
 
-// Symbols for MS mutual detection.
-int _You_must_link_with_exactly_one_OpenMP_library = 1;
-int _You_must_link_with_Intel_OpenMP_library = 1;
-#if KMP_OS_WINDOWS && (KMP_VERSION_MAJOR > 4)
-int _You_must_link_with_Microsoft_OpenMP_library = 1;
-#endif
-
 kmp_target_offload_kind_t __kmp_target_offload = tgt_default;
 
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