Parser: set type correctly for _Generic selections

src/aro/Parser.zig

@@ -8745,6 +8745,7 @@ fn genericSelection(p: *Parser) Error!Result {
             try p.list_buf.insert(list_buf_top + 1, try p.addNode(.{
                 .tag = .generic_default_expr,
                 .data = .{ .un = default.node },
+                .ty = default.ty,
             }));
             chosen = default;
         } else {
@@ -8755,11 +8756,13 @@ fn genericSelection(p: *Parser) Error!Result {
         try p.list_buf.insert(list_buf_top + 1, try p.addNode(.{
             .tag = .generic_association_expr,
             .data = .{ .un = chosen.node },
+            .ty = chosen.ty,
         }));
         if (default_tok != null) {
             try p.list_buf.append(try p.addNode(.{
                 .tag = .generic_default_expr,
-                .data = .{ .un = chosen.node },
+                .data = .{ .un = default.node },
+                .ty = default.ty,
             }));
         }
     }

test/cases/ast/generic ast.c

@@ -0,0 +1,38 @@
+var: 'int'
+ name: x
+ init:
+  generic_expr: 'int'
+   controlling:
+    int_literal: 'int' (value: 5)
+   chosen:
+    generic_association_expr: 'int'
+      int_literal: 'int' (value: 42)
+   rest:
+    generic_association_expr: 'double'
+      float_literal: 'double' (value: 32.5)
+
+var: 'int'
+ name: y
+ init:
+  generic_expr: 'int'
+   controlling:
+    int_literal: 'int' (value: 5)
+   chosen:
+    generic_association_expr: 'int'
+      int_literal: 'int' (value: 42)
+   rest:
+    generic_association_expr: 'double'
+      float_literal: 'double' (value: 32.5)
+    generic_default_expr: '[7]char'
+      string_literal_expr: '[7]char' lvalue (value: "string")
+
+var: 'double'
+ name: z
+ init:
+  implicit_cast: (int_to_float) 'double'
+    generic_expr_one: 'int'
+     controlling:
+      int_literal: 'int' (value: 5)
+     chosen:
+      int_literal: 'int' (value: 32)
+

test/cases/generic ast.c

@@ -0,0 +1,14 @@
+int x = _Generic(5,
+	int: 42,
+	double: 32.5
+);
+
+int y = _Generic(5,
+	int: 42,
+	double: 32.5,
+	default: "string"
+);
+
+double z = _Generic(5,
+	default: 32
+);