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

[Mingming Liu via llvm-commits]

================
@@ -80,6 +80,27 @@ static cl::opt<unsigned>
     ICPCSSkip("icp-csskip", cl::init(0), cl::Hidden,
               cl::desc("Skip Callsite up to this number for this compilation"));
 
+// ICP the candidate function even when only a declaration is present.
+static cl::opt<bool> ICPAllowDecls(
+    "icp-allow-decls", cl::init(false), cl::Hidden,
+    cl::desc("Promote the target candidate even when the defintion "
+             " is not available"));
+
+// ICP hot candidate functions only. When setting to false, non-cold functions
+// (warm functions) can also be promoted.
+static cl::opt<bool>
+    ICPAllowHotOnly("icp-allow-hot-only", cl::init(true), cl::Hidden,
+                    cl::desc("Promote the target candidate only if it is a "
+                             "hot function. Otherwise, warm functions can "
+                             "also be promoted"));
+
+// If one target cannot be ICP'd, proceed with the remaining targets instead
+// of exiting the callsite
----------------
mingmingl-llvm wrote:

nit: add a period to complete this sentence.

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