Refactor CMake code related to compiler warnings, enable some additional warnings (#6355)

src/util/glibc_workaround.cpp

@@ -1,31 +0,0 @@
-#ifdef GLIBC_WORKAROUND
-#include <stdexcept>
-
-// https://github.com/bitcoin/bitcoin/pull/4042
-// allows building against libstdc++-dev-4.9 while avoiding
-// GLIBCXX_3.4.20 dep
-// This is needed because libstdc++ itself uses this API - its not
-// just an issue of your code using it, ughhh
-
-// Note: only necessary on Linux
-#ifdef __linux__
-#define _ENABLE_GLIBC_WORKAROUND
-#warning building with workaround
-#else
-#warning not building with workaround
-#endif
-
-#ifdef _ENABLE_GLIBC_WORKAROUND
-namespace std
-{
-
-void __throw_out_of_range_fmt(const char *, ...) __attribute__((__noreturn__));
-void __throw_out_of_range_fmt(const char *err, ...)
-{
-    // Safe and over-simplified version. Ignore the format and print it as-is.
-    __throw_out_of_range(err);
-}
-} // namespace std
-#endif // _ENABLE_GLIBC_WORKAROUND
-
-#endif // GLIBC_WORKAROUND