Move compiler warning suppression for tests from cpp files to CMake

tests/bounds_tests.cpp

@@ -21,21 +21,6 @@
 #pragma warning(disable : 4996)  // use of function or classes marked [[deprecated]]
 #endif
 
-#if __clang__ || __GNUC__
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
-
-//disable warnings from gtest
-#pragma GCC diagnostic ignored "-Wundef"
-#endif // __clang__ || __GNUC__
-
-#if __clang__
-#pragma GCC diagnostic ignored "-Wglobal-constructors"
-#pragma GCC diagnostic ignored "-Wused-but-marked-unused"
-#pragma GCC diagnostic ignored "-Wcovered-switch-default"
-#pragma GCC diagnostic ignored "-Winconsistent-missing-destructor-override"
-#endif // __clang__
-
 #include <gtest/gtest.h>
 
 #include <gsl/multi_span> // for static_bounds, static_bounds_dynamic_range_t
@@ -122,7 +107,3 @@ TEST(bounds_tests, bounds_convertible)
 #ifdef CONFIRM_COMPILATION_ERRORS
 copy(src_span_static, dst_span_static);
 #endif
-
-#if __clang__ || __GNUC__
-#pragma GCC diagnostic pop
-#endif // __clang__ || __GNUC__