add cmake option to fall back on the fiber api do detect thread termi…

…nation on windows

CMakeLists.txt

@@ -34,6 +34,7 @@ option(MI_NO_THP            "Disable transparent huge pages support on Linux/And
 option(MI_EXTRA_CPPDEFS     "Extra pre-processor definitions (use as `-DMI_EXTRA_CPPDEFS=\"opt1=val1;opt2=val2\"`)" "")
 
 # deprecated options
+option(MI_WIN_USE_FLS       "Use Fiber local storage on Windows to detect thread termination" OFF)
 option(MI_CHECK_FULL        "Use full internal invariant checking in DEBUG mode (deprecated, use MI_DEBUG_FULL instead)" OFF)
 option(MI_USE_LIBATOMIC     "Explicitly link with -latomic (on older systems) (deprecated and detected automatically)" OFF)
 
@@ -313,6 +314,11 @@ if(MI_LIBC_MUSL)
   list(APPEND mi_defines MI_LIBC_MUSL=1)
 endif()
 
+if(MI_WIN_USE_FLS)
+  message(STATUS "Use the Fiber API to detect thread termination")
+  list(APPEND mi_defines MI_WIN_USE_FLS=1)
+endif()
+
 # On Haiku use `-DCMAKE_INSTALL_PREFIX` instead, issue #788
 # if(CMAKE_SYSTEM_NAME MATCHES "Haiku")
 #   SET(CMAKE_INSTALL_LIBDIR ~/config/non-packaged/lib)