refactor(es/parser): Remove duplicate check (#10847)

Author: bvanjoi

.changeset/light-yaks-rule.md

@@ -0,0 +1,6 @@
+---
+swc_core: patch
+swc_ecma_lexer: patch
+---
+
+refactor(es/parser): duplicate check

crates/swc_ecma_lexer/src/common/parser/expr.rs

@@ -2348,14 +2348,6 @@ pub fn parse_primary_expr_rest<'a, P: Parser<'a>>(
             !ctx.contains(Context::InGenerator),
             !ctx.contains(Context::InAsync),
         )?;
-        if id.is_reserved_in_strict_mode(
-            p.ctx().contains(Context::Module) && !p.ctx().contains(Context::InDeclare),
-        ) {
-            p.emit_strict_mode_err(
-                p.input().prev_span(),
-                SyntaxError::InvalidIdentInStrict(id.sym.clone()),
-            );
-        }
 
         if can_be_arrow
             && id.sym == "async"

crates/swc_ecma_lexer/src/common/parser/ident.rs

@@ -216,9 +216,7 @@ pub fn parse_ident<'a>(
         word = ident
     } else if t.is_yield() && incl_yield {
         word = atom!("yield")
-    } else if t.is_null() || t.is_true() || t.is_false() {
-        syntax_error!(p, p.input().prev_span(), SyntaxError::ExpectedIdent)
-    } else if t.is_keyword() {
+    } else if t.is_null() || t.is_true() || t.is_false() || t.is_keyword() {
         syntax_error!(p, p.input().prev_span(), SyntaxError::ExpectedIdent)
     } else {
         unreachable!()