[cmake] Remove custom linker flag check function

Since LLVM now requires a minimum cmake version of 3.20.0, we no longer
need this abstraction and can use the built in version directly as we do
for the other feature check functions.

clang/tools/clang-repl/CMakeLists.txt

@@ -29,7 +29,7 @@ endif()
 # gold. This flag tells the linker to build a PLT for the full address range.
 # Linkers without this flag are assumed to support proper PLTs by default.
 set(flag_long_plt "-Wl,--long-plt")
-llvm_check_linker_flag(CXX ${flag_long_plt} HAVE_LINKER_FLAG_LONG_PLT)
+check_linker_flag(CXX ${flag_long_plt} HAVE_LINKER_FLAG_LONG_PLT)
 if(HAVE_LINKER_FLAG_LONG_PLT)
   target_link_options(clang-repl PRIVATE ${flag_long_plt})
 endif()

clang/tools/driver/CMakeLists.txt

@@ -104,7 +104,7 @@ endif()
 
 if(CLANG_ORDER_FILE AND
     (LLVM_LINKER_IS_APPLE OR LLVM_LINKER_IS_GOLD OR LLVM_LINKER_IS_LLD))
-  include(LLVMCheckLinkerFlag)
+  include(CheckLinkerFlag)
 
   if (LLVM_LINKER_IS_APPLE OR (LLVM_LINKER_IS_LLD AND APPLE))
     set(LINKER_ORDER_FILE_OPTION "-Wl,-order_file,${CLANG_ORDER_FILE}")
@@ -115,7 +115,7 @@ if(CLANG_ORDER_FILE AND
   endif()
 
   # This is a test to ensure the actual order file works with the linker.
-  llvm_check_linker_flag(CXX ${LINKER_ORDER_FILE_OPTION} LINKER_ORDER_FILE_WORKS)
+  check_linker_flag(CXX ${LINKER_ORDER_FILE_OPTION} LINKER_ORDER_FILE_WORKS)
 
   # Passing an empty order file disables some linker layout optimizations.
   # To work around this and enable workflows for re-linking when the order file

clang/tools/libclang/CMakeLists.txt

@@ -190,8 +190,7 @@ if(ENABLE_SHARED)
       include(CheckLinkerFlag)
       # The Solaris 11.4 linker supports a subset of GNU ld version scripts,
       # but requires a special option to enable it.
-      llvm_check_linker_flag(CXX "-Wl,-z,gnu-version-script-compat"
-                             LINKER_SUPPORTS_Z_GNU_VERSION_SCRIPT_COMPAT)
+      check_linker_flag(CXX "-Wl,-z,gnu-version-script-compat" LINKER_SUPPORTS_Z_GNU_VERSION_SCRIPT_COMPAT)
       # Older Solaris (and illumos) linker does not support GNU ld version scripts
       # and does not support GNU version script compat.
       if (LINKER_SUPPORTS_Z_GNU_VERSION_SCRIPT_COMPAT)

llvm/cmake/modules/AddLLVM.cmake

@@ -302,8 +302,8 @@ function(add_link_opts target_name)
       elseif(${CMAKE_SYSTEM_NAME} MATCHES "SunOS" AND LLVM_LINKER_IS_SOLARISLD)
         # Support for ld -z discard-unused=sections was only added in
         # Solaris 11.4.  GNU ld ignores it, but warns every time.
-        include(LLVMCheckLinkerFlag)
-        llvm_check_linker_flag(CXX "-Wl,-z,discard-unused=sections" LINKER_SUPPORTS_Z_DISCARD_UNUSED)
+        include(CheckLinkerFlag)
+        check_linker_flag(CXX "-Wl,-z,discard-unused=sections" LINKER_SUPPORTS_Z_DISCARD_UNUSED)
         if (LINKER_SUPPORTS_Z_DISCARD_UNUSED)
           set_property(TARGET ${target_name} APPEND_STRING PROPERTY
                        LINK_FLAGS " -Wl,-z,discard-unused=sections")

llvm/cmake/modules/HandleLLVMOptions.cmake

@@ -1077,8 +1077,8 @@ if (LLVM_USE_SPLIT_DWARF AND
   if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR
       CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
     add_compile_options($<$<COMPILE_LANGUAGE:C,CXX>:-gsplit-dwarf>)
-    include(LLVMCheckLinkerFlag)
-    llvm_check_linker_flag(CXX "-Wl,--gdb-index" LINKER_SUPPORTS_GDB_INDEX)
+    include(CheckLinkerFlag)
+    check_linker_flag(CXX "-Wl,--gdb-index" LINKER_SUPPORTS_GDB_INDEX)
     append_if(LINKER_SUPPORTS_GDB_INDEX "-Wl,--gdb-index"
       CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
   endif()
@@ -1099,8 +1099,8 @@ endif()
 
 # lld doesn't print colored diagnostics when invoked from Ninja
 if (UNIX AND CMAKE_GENERATOR MATCHES "Ninja")
-  include(LLVMCheckLinkerFlag)
-  llvm_check_linker_flag(CXX "-Wl,--color-diagnostics" LINKER_SUPPORTS_COLOR_DIAGNOSTICS)
+  include(CheckLinkerFlag)
+  check_linker_flag(CXX "-Wl,--color-diagnostics" LINKER_SUPPORTS_COLOR_DIAGNOSTICS)
   append_if(LINKER_SUPPORTS_COLOR_DIAGNOSTICS "-Wl,--color-diagnostics"
     CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
 endif()

llvm/cmake/modules/HandleLLVMStdlib.cmake

@@ -13,12 +13,12 @@ if(NOT DEFINED LLVM_STDLIB_HANDLED)
   endfunction()
 
   include(CheckCXXCompilerFlag)
-  include(LLVMCheckLinkerFlag)
+  include(CheckLinkerFlag)
   set(LLVM_LIBCXX_USED 0)
   if(LLVM_ENABLE_LIBCXX)
     if(LLVM_COMPILER_IS_GCC_COMPATIBLE)
       check_cxx_compiler_flag("-stdlib=libc++" CXX_COMPILER_SUPPORTS_STDLIB)
-      llvm_check_linker_flag(CXX "-stdlib=libc++" CXX_LINKER_SUPPORTS_STDLIB)
+      check_linker_flag(CXX "-stdlib=libc++" CXX_LINKER_SUPPORTS_STDLIB)
       if(CXX_COMPILER_SUPPORTS_STDLIB AND CXX_LINKER_SUPPORTS_STDLIB)
         append("-stdlib=libc++"
           CMAKE_CXX_FLAGS CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS
@@ -36,7 +36,7 @@ if(NOT DEFINED LLVM_STDLIB_HANDLED)
     if(LLVM_COMPILER_IS_GCC_COMPATIBLE)
       check_cxx_compiler_flag("-static-libstdc++"
                               CXX_COMPILER_SUPPORTS_STATIC_STDLIB)
-      llvm_check_linker_flag(CXX "-static-libstdc++" CXX_LINKER_SUPPORTS_STATIC_STDLIB)
+      check_linker_flag(CXX "-static-libstdc++" CXX_LINKER_SUPPORTS_STATIC_STDLIB)
       if(CXX_COMPILER_SUPPORTS_STATIC_STDLIB AND
         CXX_LINKER_SUPPORTS_STATIC_STDLIB)
         append("-static-libstdc++"