[llvm] [AMDGPU] Add inreg support for SGPR arguments (PR #67182)

[Matt Arsenault via llvm-commits]

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@@ -2543,8 +2543,7 @@ bool isArgPassedInSGPR(const Argument *A) {
     return A->hasAttribute(Attribute::InReg) ||
            A->hasAttribute(Attribute::ByVal);
   default:
-    // TODO: Should calls support inreg for SGPR inputs?
-    return false;
+    return A->hasAttribute(Attribute::InReg);
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arsenm wrote:

Maybe adjust the todo to treat i1 as divergent 

https://github.com/llvm/llvm-project/pull/67182