Refactoring test to use assert_nothing_raised.

test/t/exception.rb

@@ -345,13 +345,13 @@ assert('Exception#inspect without message') do
 end
 
 assert('Exception#backtrace') do
-  begin
-    raise "get backtrace"
-  rescue => e
-    e.backtrace
+  assert_nothing_raised do
+    begin
+      raise "get backtrace"
+    rescue => e
+      e.backtrace
+    end
   end
-
-  true
 end
 
 assert('Raise in ensure') do

test/t/string.rb

@@ -476,7 +476,11 @@ assert('String#upcase!', '15.2.10.5.43') do
 end
 
 assert('String#inspect', '15.2.10.5.46') do
-  ("\1" * 100).inspect  # should not raise an exception - regress #1210
+  # should not raise an exception - regress #1210
+  assert_nothing_raised do
+  ("\1" * 100).inspect
+  end
+
   assert_equal "\"\\000\"", "\0".inspect
 end