Clarify comment in the string-offsets-table-order.ll test

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@340826 91177308-0d34-0410-b5e6-96231b3b80d8

Author: labath

test/DebugInfo/X86/string-offsets-table-order.ll

@@ -7,7 +7,9 @@
 ; still wired up correctly.
 
 ; Produced with "clang -S -emit-llvm -gdwarf-5" from source "int X;", copied
-; three times and modified by hand.
+; three times and modified by hand. The modifications consisted of modifying the
+; compilation directory and the variable names to trigger the insertion of names
+; in different order.
 
 ; CHECK: .debug_info contents:
 ; CHECK:   DW_TAG_compile_unit