[llvm] [flang-rt] replace the triple dir to 'aix' for flang-rt to be consistent with clang on AIX. (PR #130875)

[Daniel Chen via llvm-commits]

https://github.com/DanielCChen created https://github.com/llvm/llvm-project/pull/130875

This change is to put `libflang_rt.runtime.a` into `build/lib/clang/21/lib/aix/libflang_rt.runtime.a`, which is consistent with clang on AIX.

>From 558a64c6b34a591281dc633727d50bbb96c0f687 Mon Sep 17 00:00:00 2001
From: Daniel Chen <cdchen at ca.ibm.com>
Date: Tue, 11 Mar 2025 21:29:51 -0400
Subject: [PATCH] [flang-rt] replace the triple dir to 'aix' for flang-rt to be
 consistent with clang on AIX.

---
 flang-rt/cmake/modules/GetToolchainDirs.cmake | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/flang-rt/cmake/modules/GetToolchainDirs.cmake b/flang-rt/cmake/modules/GetToolchainDirs.cmake
index 426a5e8e801f3..0c8a064dce528 100644
--- a/flang-rt/cmake/modules/GetToolchainDirs.cmake
+++ b/flang-rt/cmake/modules/GetToolchainDirs.cmake
@@ -118,6 +118,9 @@ function (get_toolchain_arch_dirname outvar)
     set(target "amdgcn-amd-amdhsa")
   elseif("${arch}" MATCHES "^nvptx")
     set(target "nvptx64-nvidia-cuda")
+  elseif(UNIX AND CMAKE_SYSTEM_NAME MATCHES "AIX")
+    # Put at lib/aix to be consistent with clang on AIX.
+    string(TOLOWER "${CMAKE_SYSTEM_NAME}" target)
   else()
     set(target "${arch}${triple_suffix}")
   endif()