[ruby/irb] Provide more useful message when

`IRB::Inspector#inspect_value` errors
(https://github.com/ruby/irb/pull/511)

**Before**

```
irb(main):001:0> c = Cat.new "foo"
(Object doesn't support #inspect)
=>
```

**After**

```
irb(main):001:0> c = Cat.new "foo"
An error occurred when inspecting the object: #<NoMethodError: undefined method `is_a?' for foo:Cat

      if obj.is_a?(String)
            ^^^^^^>
Result of Kernel#inspect: #<Cat:0x0000000109090d80 @name="foo">
=>
```

1 files changed, 13 insertions, 3 deletions

diff --git a/lib/irb/inspector.rb b/lib/irb/inspector.rb
index 50f6ebf383..bdfa282f0d 100644
--- a/lib/irb/inspector.rb
+++ b/lib/irb/inspector.rb
@@ -35,6 +35,7 @@ module IRB # :nodoc:
   #     irb(main):001:0> "what?" #=> omg! what?
   #
   class Inspector
+    KERNEL_INSPECT = Object.instance_method(:inspect)
     # Default inspectors available to irb, this includes:
     #
     # +:pp+::       Using Kernel#pretty_inspect
@@ -93,9 +94,18 @@ module IRB # :nodoc:
     # Proc to call when the input is evaluated and output in irb.
     def inspect_value(v)
       @inspect.call(v)
-    rescue
-      puts "(Object doesn't support #inspect)"
-      ''
+    rescue => e
+      puts "An error occurred when inspecting the object: #{e.inspect}"
+
+      begin
+        # TODO: change this to bind_call when we drop support for Ruby 2.6
+        puts "Result of Kernel#inspect: #{KERNEL_INSPECT.bind(v).call}"
+        ''
+      rescue => e
+        puts "An error occurred when running Kernel#inspect: #{e.inspect}"
+        puts e.backtrace.join("\n")
+        ''
+      end
     end
   end