Adjust tests for JuliaLang/julia#47077 (backlport of #784)

(cherry picked from commit 6e1b40c)

Author: martinholters

test/runtests.jl

@@ -1165,7 +1165,7 @@ end
         DivideError: integer division error
         Stacktrace:.*
 
-        caused by: UndefVarError: __not_a_binding__ not defined
+        caused by: UndefVarError: `?__not_a_binding__`? not defined
         Stacktrace:.*
         """s, sprint(show, excs_with_bts))
 
@@ -1174,23 +1174,23 @@ end
         2-element ExceptionStack:
         DivideError: integer division error
 
-        caused by: UndefVarError: __not_a_binding__ not defined"""s,
+        caused by: UndefVarError: `?__not_a_binding__`? not defined"""s,
         sprint(show, excs_sans_bts))
 
         # Check that the ExceptionStack with backtraces `display_error`s correctly:
         @test occursin(r"""
         ERROR: DivideError: integer division error
         Stacktrace:.*
 
-        caused by: UndefVarError: __not_a_binding__ not defined
+        caused by: UndefVarError: `?__not_a_binding__`? not defined
         Stacktrace:.*
         """s, sprint(Base.display_error, excs_with_bts))
 
         # Check that the ExceptionStack without backtraces `display_error`s correctly:
         @test occursin(r"""
         ERROR: DivideError: integer division error
 
-        caused by: UndefVarError: __not_a_binding__ not defined"""s,
+        caused by: UndefVarError: `?__not_a_binding__`? not defined"""s,
         sprint(Base.display_error, excs_sans_bts))
     else
         # Due to runtime limitations, julia-1.0 only retains the last exception.