[NFC][Codegen] Use MaybeAlign + APInt::getLimitedValue() when creating Alignment attr

Summary: Just an NFC code cleanup i stumbled upon when stumbling through clang alignment attribute handling.

Reviewers: erichkeane, gchatelet, courbet, jdoerfert

Reviewed By: gchatelet

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D72993

clang/lib/CodeGen/CGCall.cpp

@@ -2440,9 +2440,8 @@ void CodeGenFunction::EmitFunctionProlog(const CGFunctionInfo &FI,
               EmitScalarExpr(AVAttr->getAlignment());
             llvm::ConstantInt *AlignmentCI =
               cast<llvm::ConstantInt>(AlignmentValue);
-            unsigned Alignment = std::min((unsigned)AlignmentCI->getZExtValue(),
-                                          +llvm::Value::MaximumAlignment);
-            AI->addAttrs(llvm::AttrBuilder().addAlignmentAttr(Alignment));
+            AI->addAttrs(llvm::AttrBuilder().addAlignmentAttr(llvm::MaybeAlign(
+                AlignmentCI->getLimitedValue(llvm::Value::MaximumAlignment))));
           }
         }