gbuild: LinkTarget: try to fix gb_LinkTarget_add_auxtarget for make 3.81
gbuild: LinkTarget: try to fix gb_LinkTarget_add_auxtarget for make 3.81

Apparently make 3.81 has trouble with the wildcard in there, it never
seems to find the file... implement the test in shell instead, since we
invoke a command on both branches it shouldn't be slower.

Change-Id: I93cc2cf09ae8af1d9379fde314a44ef92a28b434

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core