[libc] add loongarch32 and loongarch64 config

Author: RossComputerGuy

libc/cmake/modules/LLVMLibCArchitectures.cmake

@@ -45,6 +45,10 @@ function(get_arch_and_system_from_triple triple arch_var sys_var)
     set(target_arch "i386")
   elseif(target_arch MATCHES "^(powerpc|ppc)")
     set(target_arch "power")
+  elseif(target_arch MATCHES "^loongarch32")
+    set(target_arch "loongarch32")
+  elseif(target_arch MATCHES "^loongarch64")
+    set(target_arch "loongarch64")
   elseif(target_arch MATCHES "^riscv32")
     set(target_arch "riscv32")
   elseif(target_arch MATCHES "^riscv64")
@@ -154,6 +158,10 @@ elseif(LIBC_TARGET_ARCHITECTURE STREQUAL "x86_64")
   set(LIBC_TARGET_ARCHITECTURE_IS_X86_64 TRUE)
 elseif(LIBC_TARGET_ARCHITECTURE STREQUAL "i386")
   set(LIBC_TARGET_ARCHITECTURE_IS_X86 TRUE)
+elseif(LIBC_TARGET_ARCHITECTURE STREQUAL "loongarch32")
+  set(LIBC_TARGET_ARCHITECTURE_IS_LOONGARCH32 TRUE)
+elseif(LIBC_TARGET_ARCHITECTURE STREQUAL "loongarch64")
+  set(LIBC_TARGET_ARCHITECTURE_IS_LOONGARCH64 TRUE)
 elseif(LIBC_TARGET_ARCHITECTURE STREQUAL "riscv64")
   set(LIBC_TARGET_ARCHITECTURE_IS_RISCV64 TRUE)
   set(LIBC_TARGET_ARCHITECTURE "riscv")