Move Thread::Backtrace::Location specs from TruffleRuby

* And generalize them so they are valid for all Ruby implementations.

Author: eregon

spec/ruby/core/thread/backtrace/location/lineno_spec.rb

@@ -10,4 +10,14 @@
   it 'returns the absolute path of the call frame' do
     @frame.lineno.should == @line
   end
+
+  it 'should be the same line number as in #to_s, including for core methods' do
+    # Get the caller_locations from a call made into a core library method
+    locations = [:non_empty].map { caller_locations }[0]
+
+    locations.each do |location|
+      line_number = location.to_s[/:(\d+):/, 1]
+      location.lineno.should == Integer(line_number)
+    end
+  end
 end

spec/ruby/core/thread/backtrace/location/path_spec.rb

@@ -87,6 +87,18 @@
     end
   end
 
+  it 'should be the same path as in #to_s, including for core methods' do
+    # Get the caller_locations from a call made into a core library method
+    locations = [:non_empty].map { caller_locations }[0]
+
+    locations.each do |location|
+      filename = location.to_s[/^(.+):\d+:/, 1]
+      path = location.path
+
+      path.should == filename
+    end
+  end
+
   context "canonicalization" do
     platform_is_not :windows do
       before :each do