[clang] [clang][driver][clang-cl] Support `--precompile` and `-fmodule-*` options in Clang-CL (PR #98761)

[Chuanqi Xu via cfe-commits]

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@@ -0,0 +1,65 @@
+// REQUIRES: system-windows
+
+// RUN: rm -rf %t
+// RUN: mkdir -p %t
+// RUN: split-file %s %t
+
+// RUN: %clang_cl /std:c++20 --precompile "%/t/Hello.cppm" "/Fo%/t/Hello.pcm"
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ChuanqiXu9 wrote:

Oh, sorry. It turns to be my bad. We should check `-emit-module-interface` for `--precompile` instead. I didn't think enough. And since we will check each line once with a `CHECK` but the output of `-###` is going to be in one line. So it may not be good to have 3 `CHECK` in one file. We can either split them by `split-file` or using different prefix for `FileCheck`.

https://github.com/llvm/llvm-project/pull/98761