[llvm] [ICP] Add a few tunings to indirect-call-promotion (PR #149892)

[Mingming Liu via llvm-commits]

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@@ -63,8 +63,8 @@ extern cl::opt<bool> EnableVTableProfileUse;
 
 // Command line option to disable indirect-call promotion with the default as
 // false. This is for debug purpose.
-static cl::opt<bool> DisableICP("disable-icp", cl::init(false), cl::Hidden,
-                                cl::desc("Disable indirect call promotion"));
+cl::opt<bool> DisableICP("disable-icp", cl::init(false), cl::Hidden,
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mingmingl-llvm wrote:

nit: afaikt it's more conventional to have `static` keyword for an `cl::opt` when the option is only used in one cpp file. It seems this option isn't used in other files in this PR, and I think we should re-add the `static` keyword.

https://github.com/llvm/llvm-project/pull/149892