[clang] [clang] Add managarm support (PR #139271)

[Fangrui Song via cfe-commits]

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@@ -1622,6 +1622,11 @@
 // RUN: %clang_cc1 -x c -std=c99 -E -dM -ffreestanding -triple=amd64-unknown-openbsd < /dev/null | FileCheck -match-full-lines -check-prefix OPENBSD-STDC-N %s
 // OPENBSD-STDC-N-NOT:#define __STDC_NO_THREADS__ 1
 //
+// RUN: %clang_cc1 -triple=aarch64-unknown-managarm-mlibc -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix MANAGARM %s
+// RUN: %clang_cc1 -triple=riscv64-unknown-managarm-mlibc -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix MANAGARM %s
+// RUN: %clang_cc1 -triple=x86_64-unknown-managarm-mlibc -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix MANAGARM %s
+// MANAGARM: #define __managarm__ 1
+//
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MaskRay wrote:

When you are adding new lines, follow the recommended practice and `s/^\/\/$//`

https://github.com/llvm/llvm-project/pull/139271