[clang] [flang] [mlir] [flang] Add basic -mtune support (PR #95043)

[Alexis Perry-Holby via cfe-commits]

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@@ -0,0 +1,9 @@
+; RUN: mlir-translate -import-llvm -split-input-file %s | FileCheck %s
+
+; CHECK-LABEL: llvm.func @tune_cpu()
+; CHECK-SAME: tune_cpu = "pentium4"
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AlexisPerry wrote:

Alright, after some digging, I can confirm that `tune-cpu` is listed among the `kExplicitAttributes` and that these attributes are expressly excluded from being added to the passthrough dictionary based on the code in `processPassthroughAttrs` in `ModuleImport.cpp`.

https://github.com/llvm/llvm-project/pull/95043