[Mac/GN] dSYM output always goes in root_out_dir, so specify it in linker outputs.

build/toolchain/mac/BUILD.gn

Index: build/toolchain/mac/BUILD.gn
diff --git a/build/toolchain/mac/BUILD.gn b/build/toolchain/mac/BUILD.gn
index 1fdc1eef3175805485521607d667a19981de86e3..c96628c3f931faf3d008e339647d54d3d9d221d6 100644
--- a/build/toolchain/mac/BUILD.gn
+++ b/build/toolchain/mac/BUILD.gn
@@ -193,7 +193,7 @@ template("mac_toolchain") {
       depend_output = tocname
 
       if (enable_dsyms) {
-        outputs += [ dylib + ".dSYM/" ]
+        outputs += [ "{{root_out_dir}}/{{target_output_name}}{{output_extension}}.dSYM/" ]
       }
     }
 
@@ -224,7 +224,7 @@ template("mac_toolchain") {
       ]
 
       if (enable_dsyms) {
-        outputs += [ sofile + ".dSYM/" ]
+        outputs += [ "{{root_out_dir}}/{{target_output_name}}{{output_extension}}.dSYM/" ]
       }
     }
 
@@ -248,7 +248,7 @@ template("mac_toolchain") {
       ]
 
       if (enable_dsyms) {
-        outputs += [ outfile + ".dSYM/" ]
+        outputs += [ "{{root_out_dir}}/{{target_output_name}}{{output_extension}}.dSYM/" ]
       }
 
       default_output_dir = "{{root_out_dir}}"