feat(json): Implement json-parse-with-source proposal (ES2026) (boa-dev#4873)

Related: https://github.com/tc39/proposal-json-parse-with-source

It changes the following:

- Implement `JSON.rawJSON(text)`: creates frozen raw JSON objects with
`[[IsRawJSON]]` internal slot and a `rawJSON` property. Validates input
is a valid JSON primitive (not object/array), rejects empty and
whitespace-padded strings.
- Implement `JSON.isRawJSON(value)`: checks for the `[[IsRawJSON]]`
internal slot.
- Update `JSON.stringify` to serialize raw JSON objects by outputting
their `rawJSON` property value directly.
- Implement `JSON.parse` reviver `context.source`: the reviver function
now receives a third `context` argument. For primitive JSON values,
`context` contains a
[source](cci:1://file:///d:/boa/core/engine/src/builtins/json/mod.rs:188:0-193:1)
property with the original source text (e.g., `"1.1e1"` instead of
`"11"`). For objects/arrays, `context` is an empty object. A
value-matching guard ensures
[source](cci:1://file:///d:/boa/core/engine/src/builtins/json/mod.rs:188:0-193:1)
is omitted when the reviver forward-modifies values during iteration.
- Add a `JsonNode` source tree builder that parses JSON to extract
byte-accurate source text spans for all primitive values.
- Remove `"json-parse-with-source"` from ignored features in
[test262_config.toml](cci:7://file:///d:/boa/test262_config.toml:0:0-0:0).

**Test262 Results: 165/165 (100% conformance)**

| Suite | Pass | Total |
|-------|------|-------|
| `JSON.parse` | 77 | 77 |
| `JSON.stringify` | 66 | 66 |
| `JSON.rawJSON` | 10 | 10 |
| `JSON.isRawJSON` | 6 | 6 |

---------

Co-authored-by: Elior Nguyen <anhtunguyendev@wavenet.com.tw>

Author: xcb3d

core/ast/src/expression/literal/mod.rs

@@ -17,7 +17,7 @@ pub use object::{ObjectLiteral, ObjectMethodDefinition, PropertyDefinition};
 pub use template::{TemplateElement, TemplateLiteral};
 
 use crate::{
-    Span, Spanned,
+    LinearSpan, LinearSpanIgnoreEq, Span, Spanned,
     visitor::{VisitWith, Visitor, VisitorMut},
 };
 use boa_interner::{Interner, Sym, ToInternedString};
@@ -41,6 +41,7 @@ use super::Expression;
 pub struct Literal {
     kind: LiteralKind,
     span: Span,
+    linear_span: LinearSpanIgnoreEq,
 }
 
 impl Literal {
@@ -51,6 +52,22 @@ impl Literal {
         Self {
             kind: kind.into(),
             span,
+            linear_span: LinearSpanIgnoreEq(LinearSpan::default()),
+        }
+    }
+
+    /// Create a new [`Literal`] with a [`LinearSpan`] for source text tracking.
+    #[inline]
+    #[must_use]
+    pub fn with_linear_span<T: Into<LiteralKind>>(
+        kind: T,
+        span: Span,
+        linear_span: LinearSpan,
+    ) -> Self {
+        Self {
+            kind: kind.into(),
+            span,
+            linear_span: LinearSpanIgnoreEq(linear_span),
         }
     }
 
@@ -68,6 +85,13 @@ impl Literal {
         &mut self.kind
     }
 
+    /// Get the [`LinearSpan`] of this literal in the source text.
+    #[inline]
+    #[must_use]
+    pub const fn linear_span(&self) -> LinearSpan {
+        self.linear_span.0
+    }
+
     /// Get position of the node.
     #[inline]
     #[must_use]