Merge pull request #7245 from Morph1984/compile-opt-desc

CMakeLists: Document the /GT compile option

src/CMakeLists.txt

@@ -32,6 +32,7 @@ if (MSVC)
     # /Zc:externConstexpr - Allow extern constexpr variables to have external linkage, like the standard mandates
     # /Zc:inline          - Let codegen omit inline functions in object files
     # /Zc:throwingNew     - Let codegen assume `operator new` (without std::nothrow) will never return null
+    # /GT                 - Supports fiber safety for data allocated using static thread-local storage
     add_compile_options(
         /MP
         /Zi