tests: do not check all fields of UndefVarError for egal (#10)

Refs: JuliaLang/julia#51979

Author: vtjnash

test/distributed_exec.jl

@@ -967,17 +967,19 @@ end
 # issue #16091
 mutable struct T16091 end
 wid = workers()[1]
-@test try
+try
     remotecall_fetch(()->T16091, wid)
-    false
+    @test "unreachable" === true
 catch ex
-    ((ex::RemoteException).captured::CapturedException).ex === UndefVarError(:T16091)
+    ex = ((ex::RemoteException).captured::CapturedException).ex
+    @test (ex::UndefVarError).var === :T16091
 end
-@test try
+try
     remotecall_fetch(identity, wid, T16091)
-    false
+    @test "unreachable" === true
 catch ex
-    ((ex::RemoteException).captured::CapturedException).ex === UndefVarError(:T16091)
+    ex = ((ex::RemoteException).captured::CapturedException).ex
+    @test (ex::UndefVarError).var === :T16091
 end
 
 f16091a() = 1
@@ -1555,7 +1557,8 @@ try
 catch ex
     @test isa(ex.captured.ex.exceptions[1].ex, ErrorException)
     @test occursin("BoundsError", ex.captured.ex.exceptions[1].ex.msg)
-    @test ex.captured.ex.exceptions[2].ex == UndefVarError(:DontExistOn1)
+    ex = ex.captured.ex.exceptions[2].ex
+    @test (ex::UndefVarError).var === :DontExistOn1
 end
 
 let