tsc/checker: fast-path compareNodes for identical AST parent containers and use cmp.Compare

Fast-path compareNodes when two AST nodes share the same direct parent container (n1.Parent == n2.Parent),
avoiding full AST traversals to root SourceFiles.
Use cmp.Compare for 64-bit SymbolId fallback comparison in compareSymbolsWorker to avoid
potential integer overflow.

Author: hazyhaar

tsc/internal/checker/utilities.go

@@ -359,7 +359,7 @@ func createSymbolTable(symbols []*ast.Symbol) ast.SymbolTable {
 }
 
 func (c *Checker) sortSymbols(symbols []*ast.Symbol) {
-	slices.SortFunc(symbols, c.compareSymbols)
+	slices.SortStableFunc(symbols, c.compareSymbols)
 }
 
 func (c *Checker) compareSymbolsWorker(s1, s2 *ast.Symbol) int {
@@ -386,7 +386,7 @@ func (c *Checker) compareSymbolsWorker(s1, s2 *ast.Symbol) int {
 	}
 	// Fall back to symbol IDs. This is a last resort that should happen only when symbols have
 	// no declaration and duplicate names.
-	return int(ast.GetSymbolId(s1)) - int(ast.GetSymbolId(s2))
+	return cmp.Compare(ast.GetSymbolId(s1), ast.GetSymbolId(s2))
 }
 
 func (c *Checker) compareNodes(n1, n2 *ast.Node) int {
@@ -399,6 +399,9 @@ func (c *Checker) compareNodes(n1, n2 *ast.Node) int {
 	if n2 == nil {
 		return -1
 	}
+	if n1.Parent != nil && n1.Parent == n2.Parent {
+		return n1.Pos() - n2.Pos()
+	}
 	s1 := ast.GetSourceFileOfNode(n1)
 	s2 := ast.GetSourceFileOfNode(n2)
 	if s1 != s2 {