[clang] [Clang] [docs] [MSVC] Add sections on `__forceinline` and intrinsic behaviour differences between Clang and MSVC (PR #99426)

[Reid Kleckner via cfe-commits]

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@@ -154,3 +154,133 @@ a hint suggesting how to fix the problem.
 As of this writing, Clang is able to compile a simple ATL hello world
 application.  There are still issues parsing WRL headers for modern Windows 8
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rnk wrote:

"modern Windows 8" is obviously stale :) , but not necessarily relevant to this PR

https://github.com/llvm/llvm-project/pull/99426