[clang] [Driver] Support -mcmodel= for LoongArch (PR #72514)

[Fangrui Song via cfe-commits]

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@@ -15,6 +15,15 @@
 // RUN: not %clang -### -c --target=aarch64 -mcmodel=medium %s 2>&1 | FileCheck --check-prefix=ERR-MEDIUM %s
 // RUN: not %clang -### -c --target=aarch64 -mcmodel=kernel %s 2>&1 | FileCheck --check-prefix=ERR-KERNEL %s
 // RUN: not %clang --target=aarch64_32-linux -### -S -mcmodel=small %s 2>&1 | FileCheck --check-prefix=ERR-AARCH64_32 %s
+// RUN: %clang --target=loongarch64 -### -S -mcmodel=small %s 2>&1 | FileCheck --check-prefix=SMALL %s
+// RUN: %clang --target=loongarch64 -### -S -mcmodel=normal %s 2>&1 | FileCheck --check-prefix=SMALL %s
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MaskRay wrote:

If `-mcmodel=normal` is canonical, we probably should not add Clang-specific alias `small`. Reject `normal`.

https://github.com/llvm/llvm-project/pull/72514