To move the find_package requirment to the top leverl cmake file.

Author: DanielCChen

flang-rt/CMakeLists.txt

@@ -245,6 +245,8 @@ check_cxx_compiler_flag("-UTESTFLAG" FLANG_RT_SUPPORTS_UNDEFINE_FLAG)
 # Check whether -fno-lto is supported.
 check_cxx_compiler_flag(-fno-lto FLANG_RT_HAS_FNO_LTO_FLAG)
 
+# Search for pthread library
+find_package(Threads REQUIRED)
 
 # function checks
 find_package(Backtrace)

flang-rt/cmake/modules/AddFlangRT.cmake

@@ -142,7 +142,6 @@ function (add_flangrt_library name)
   endif ()
   if (build_shared)
     add_library("${name_shared}" SHARED ${extra_args} ${ARG_ADDITIONAL_HEADERS} ${ARG_UNPARSED_ARGUMENTS})
-    find_package(Threads REQUIRED)
     target_link_libraries(${name_shared} PUBLIC Threads::Threads)
   endif ()