[clang-repl] Limit use of PLT offset flag to linkers that support it

Follow-up fix from llvm/llvm-project#78959

Author: weliveindetail

clang/tools/clang-repl/CMakeLists.txt

@@ -24,6 +24,11 @@ if(CLANG_PLUGIN_SUPPORT)
 endif()
 
 string(TOUPPER ${CMAKE_SYSTEM_PROCESSOR} system_processor)
-if(${system_processor} MATCHES "ARM")
-  target_link_options(clang-repl PRIVATE LINKER:--long-plt)
+if(system_processor MATCHES "ARM")
+  set(FLAG_LONG_PLT "-Wl,--long-plt")
+  llvm_check_linker_flag(CXX ${FLAG_LONG_PLT} LINKER_HAS_FLAG_LONG_PLT)
+  # Linkers without this flag are assumed to have long PLTs by default
+  if(LINKER_HAS_FLAG_LONG_PLT)
+    target_link_options(clang-repl PRIVATE ${FLAG_LONG_PLT})
+  endif()
 endif()