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, 2 insertions, 0 deletions

diff --git a/rubyparser.h b/rubyparser.h
index fa2e2af264..e3c7eae05a 100644
--- a/rubyparser.h
+++ b/rubyparser.h
@@ -725,6 +725,8 @@ typedef struct RNode_EVSTR {
     NODE node;
 
     struct RNode *nd_body;
+    rb_code_location_t opening_loc;
+    rb_code_location_t closing_loc;
 } rb_node_evstr_t;
 
 typedef struct RNode_REGX {     /* also RNode_MATCH */