bugfix: fix tilelang g_tilingKey multiple definition across kernel families.

[fengz72]

Description

修复不同 TileLang kernel family 共享相同 variant key 后缀（如 w4、w5、w6）时 g_tilingKey 多重定义的链接错误。

根因

_run_variant_worker 中将 g_tilingKey 定义为 g_tilingKey__{variant_key}，当 spec_verify_token_update 和 spec_verify_attention_tiling_update 两个 family 使用相同的 variant 后缀（w4/w5/w6）时，生成相同的全局符号名。两者同时链接进 libtilelang_kernels.a 后，链接器报 multiple definition 错误：
ld: multiple definition of g_tilingKey__w4'
ld: multiple definition of g_tilingKey__w5'
ld: multiple definition of `g_tilingKey__w6'

修复方案

在 -Dg_tilingKey 宏定义中加入 kernel_name 前缀：
-Dg_tilingKey=g_tilingKey_{kernel_name}{variant_key}
使每个 family 生成唯一符号（如 g_tilingKey__spec_verify_token_update_w4 与 g_tilingKey__spec_verify_attention_tiling_update_w4），消除冲突。
kernel_family_builder.py 本身已包含在缓存依赖文件列表中，修改后自动触发所有 variant 重新编译，无需手动清理缓存

Related Issues

Change Type

• Bug fix
• New feature
• Performance improvement
• Refactor
• Documentation
• Test
• Build or CI

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