[libc][CMake] fix CMake configure issues on openSUSE (#79751)

Author: Lancern

libc/cmake/modules/LLVMLibCArchitectures.cmake

@@ -165,10 +165,13 @@ if(LIBC_TARGET_OS STREQUAL "baremetal")
   set(LIBC_TARGET_OS_IS_BAREMETAL TRUE)
 elseif(LIBC_TARGET_OS STREQUAL "linux")
   set(LIBC_TARGET_OS_IS_LINUX TRUE)
-elseif(LIBC_TARGET_OS STREQUAL "poky")
+elseif(LIBC_TARGET_OS STREQUAL "poky" OR LIBC_TARGET_OS STREQUAL "suse")
   # poky are ustom Linux-base systems created by yocto. Since these are Linux
   # images, we change the LIBC_TARGET_OS to linux. This define is used to
   # include the right directories during compilation.
+  #
+  # openSUSE uses different triple format which causes LIBC_TARGET_OS to be
+  # computed as "suse" instead of "linux".
   set(LIBC_TARGET_OS_IS_LINUX TRUE)
   set(LIBC_TARGET_OS "linux")
 elseif(LIBC_TARGET_OS STREQUAL "darwin")