[MLIR] Ensure that out-of-tree users have an mlir-generic-headers target

Prior change introduces this target, but we need it for out-of-tree users
too

diff --git a/mlir/cmake/modules/MLIRConfig.cmake.in b/mlir/cmake/modules/MLIRConfig.cmake.in
index da51876..e8822e5 100644 (file)
--- a/mlir/cmake/modules/MLIRConfig.cmake.in
+++ b/mlir/cmake/modules/MLIRConfig.cmake.in
@@ -32,6 +32,9 @@ endif()
 if(NOT TARGET mlir-headers)
   add_custom_target(mlir-headers)
 endif()
+if(NOT TARGET mlir-generic-headers)
+  add_custom_target(mlir-generic-headers)
+endif()
 if(NOT TARGET mlir-doc)
   add_custom_target(mlir-doc)
 endif()