restore '--allow-shlib-undefined' flag

cime_config/machines/cmake_macros/crayclanggpu_frontier.cmake

@@ -33,7 +33,7 @@ set(HAS_F2008_CONTIGUOUS "TRUE")
 # -Wl,--allow-shlib-undefined was added to address rocm 5.4.3 Fortran linker issue:
 # /opt/rocm-5.4.3/lib/libhsa-runtime64.so.1: undefined reference to `std::condition_variable::wait(std::unique_lock<std::mutex>&)@GLIBCXX_3.4.30'
 # AMD started building with GCC 12.2.0, which brings in a GLIBCXX symbol that isn't in CCE's default GCC toolchain.
-string(APPEND CMAKE_EXE_LINKER_FLAGS " -Wl,--allow-multiple-definition")
+string(APPEND CMAKE_EXE_LINKER_FLAGS " -Wl,--allow-shlib-undefined -Wl,--allow-multiple-definition")
 
 # Switching to O3 for performance benchmarking
 # Will revisit any failing tests