test: update syntax tests

Author: inkydragon

test/syntax.jl

@@ -377,8 +377,8 @@ add_method_to_glob_fn!()
 @test_parseerror "function finally() end"
 
 # PR #16170
-@test Meta.lower(Main, Meta.parse("true(x) = x")) == Expr(:error, "invalid function name \"true\"")
-@test Meta.lower(Main, Meta.parse("false(x) = x")) == Expr(:error, "invalid function name \"false\"")
+@test Meta.lower(Main, Meta.parse("true(x) = x")) == Expr(:error, "\"true\" is not a valid function argument name")
+@test Meta.lower(Main, Meta.parse("false(x) = x")) == Expr(:error, "\"false\" is not a valid function argument name")
 
 # issue #16355
 @test Meta.lower(Main, :(f(d:Int...) = nothing)) == Expr(:error, "\"d:Int\" is not a valid function argument name")