[lld] [libc++] Use -nostdlib++ on GCC unconditionally (PR #68832)

[Louis Dionne via llvm-commits]

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@@ -108,22 +97,18 @@ if(WIN32 AND NOT MINGW)
   # TODO(compnerd) do we want to support an emulation layer that allows for the
   # use of pthread-win32 or similar libraries to emulate pthreads on Windows?
   set(LIBCXX_HAS_PTHREAD_LIB NO)
-  set(LIBCXX_HAS_M_LIB NO)
   set(LIBCXX_HAS_RT_LIB NO)
   set(LIBCXX_HAS_ATOMIC_LIB NO)
 elseif(APPLE)
   set(LIBCXX_HAS_PTHREAD_LIB NO)
-  set(LIBCXX_HAS_M_LIB NO)
   set(LIBCXX_HAS_RT_LIB NO)
   set(LIBCXX_HAS_ATOMIC_LIB NO)
 elseif(FUCHSIA)
-  set(LIBCXX_HAS_M_LIB NO)
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ldionne wrote:

According to https://godbolt.org/z/9E9e474f1, it is. This is also confirmed by the fact that our tests are not failing even though I removed it.

https://github.com/llvm/llvm-project/pull/68832