restore amdflang symlink (llvm#1595)

Author: ronlieb

clang/tools/amdllvm/CMakeLists.txt

@@ -6,8 +6,14 @@ add_clang_tool(amdllvm
     amdllvm.cpp
 )
 
+option(CLANG_LINK_FLANG "Create flang install link to clang" ON)
+
 list(APPEND CLANG_LINKS_TO_CREATE clang clang++ clang-cl clang-cpp clang-${CLANG_VERSION_MAJOR} lld)
 
+if(CLANG_LINK_FLANG)
+    list(APPEND CLANG_LINKS_TO_CREATE flang)
+endif()
+
 foreach(link ${CLANG_LINKS_TO_CREATE})
     add_clang_symlink("amd${link}" amdllvm)
 endforeach()