add behavior test @tagName with signed values

Author: Luukdegram

test/behavior/enum.zig

@@ -1048,6 +1048,22 @@ test "@tagName on enum literals" {
     try comptime expect(mem.eql(u8, @tagName(.FooBar), "FooBar"));
 }
 
+test "tag name with signed enum values" {
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest;
+
+    const LocalFoo = enum(isize) {
+        alfa = 62,
+        bravo = 63,
+        charlie = 64,
+        delta = 65,
+    };
+    var b = LocalFoo.bravo;
+    try expect(mem.eql(u8, @tagName(b), "bravo"));
+}
+
 test "enum literal casting to optional" {
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;