Implement EVSTR NODE locations

The following Location information has been added This is the information required for parse.y to be a universal parser:

```
❯ ruby --parser=prism --dump=parsetree -e '"#{foo}"'
@ ProgramNode (location: (1,0)-(1,8))
+-- locals: []
+-- statements:
    @ StatementsNode (location: (1,0)-(1,8))
    +-- body: (length: 1)
        +-- @ InterpolatedStringNode (location: (1,0)-(1,8))
            +-- InterpolatedStringNodeFlags: nil
            +-- opening_loc: (1,0)-(1,1) = "\""
            +-- parts: (length: 1)
            |   +-- @ EmbeddedStatementsNode (location: (1,1)-(1,7))
            |       +-- opening_loc: (1,1)-(1,3) = "\#{"
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
            |       +-- statements:
            |       |   @ StatementsNode (location: (1,3)-(1,6))
            |       |   +-- body: (length: 1)
            |       |       +-- @ CallNode (location: (1,3)-(1,6))
            |       |           +-- CallNodeFlags: variable_call, ignore_visibility
            |       |           +-- receiver: nil
            |       |           +-- call_operator_loc: nil
            |       |           +-- name: :foo
            |       |           +-- message_loc: (1,3)-(1,6) = "foo"
            |       |           +-- opening_loc: nil
            |       |           +-- arguments: nil
            |       |           +-- closing_loc: nil
            |       |           +-- block: nil
            |       +-- closing_loc: (1,6)-(1,7) = "}"
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
            +-- closing_loc: (1,7)-(1,8) = "\""
```

1 files changed, 8 insertions, 0 deletions

diff --git a/test/ruby/test_ast.rb b/test/ruby/test_ast.rb
index 58d22149b7..4e449410f1 100644
--- a/test/ruby/test_ast.rb
+++ b/test/ruby/test_ast.rb
@@ -1376,6 +1376,14 @@ dummy
       assert_locations(node.children[-1].locations, [[1, 0, 1, 17], [1, 0, 1, 4], [1, 14, 1, 17]])
     end
 
+    def test_evstr_locations
+      node = ast_parse('"#{foo}"')
+      assert_locations(node.children[-1].children[1].locations, [[1, 0, 1, 8], [1, 1, 1, 3], [1, 6, 1, 7]])
+
+      node = ast_parse('"#$1"')
+      assert_locations(node.children[-1].children[1].locations, [[1, 0, 1, 5], [1, 1, 1, 2], nil])
+    end
+
     def test_if_locations
       node = ast_parse("if cond then 1 else 2 end")
       assert_locations(node.children[-1].locations, [[1, 0, 1, 25], [1, 0, 1, 2], [1, 8, 1, 12], [1, 22, 1, 25]])