[llvm] [TTI][AMDGPU] Allow targets to adjust `LastCallToStaticBonus` via `getInliningLastCallToStaticBonus` (PR #111311)

[Matt Arsenault via llvm-commits]

================
@@ -240,6 +240,11 @@ class GCNTTIImpl final : public BasicTTIImplBase<GCNTTIImpl> {
   bool areInlineCompatible(const Function *Caller,
                            const Function *Callee) const;
 
+  int getInliningLastCallToStaticBonus() const {
+    // InlineConstants::LastCallToStaticBonus * 11 where 11 is AMDGPU's inlining
+    // threshold multiplier.
+    return 165000;
----------------
arsenm wrote:

It makes no sense to have this multiplier applied to some places and not the others. Do not do things out of fear of touching other targets, that's how we end up with a lot of the messes we already have 

https://github.com/llvm/llvm-project/pull/111311