llvm: fix llvm@14 build with apple-clang-15 (#40191)

* llvm: fix llvm@14 build with apple-clang-15

* fix formatting

---------

Co-authored-by: Adam J. Stewart <ajstewart426@gmail.com>

var/spack/repos/builtin/packages/llvm/package.py

@@ -572,6 +572,8 @@ class Llvm(CMakePackage, CudaPackage):
     patch("add-include-for-libelf-llvm-12-14.patch", when="@12:14")
     patch("add-include-for-libelf-llvm-15.patch", when="@15")
 
+    patch("sanitizer-platform-limits-posix-xdr-macos.patch", when="@10:14 platform=darwin")
+
     @when("@14:17")
     def patch(self):
         # https://github.com/llvm/llvm-project/pull/69458
@@ -940,6 +942,26 @@ def cmake_args(self):
 
         # Semicolon seperated list of runtimes to enable
         if runtimes:
+            # The older versions are not careful enough with the order of the runtimes.
+            # Instead of applying
+            # https://github.com/llvm/llvm-project/commit/06400a0142af8297b5d39b8f34a7c59db6f9910c,
+            # which might be incompatible with the version that we install,
+            # we sort the runtimes here according to the same order as
+            # in the aforementioned commit:
+            if self.spec.satisfies("@:14"):
+                runtimes_order = [
+                    "libc",
+                    "libunwind",
+                    "libcxxabi",
+                    "libcxx",
+                    "compiler-rt",
+                    "openmp",
+                ]
+                runtimes.sort(
+                    key=lambda x: runtimes_order.index(x)
+                    if x in runtimes_order
+                    else len(runtimes_order)
+                )
             cmake_args.extend(
                 [
                     define("LLVM_ENABLE_RUNTIMES", runtimes),

var/spack/repos/builtin/packages/llvm/sanitizer-platform-limits-posix-xdr-macos.patch

@@ -0,0 +1,11 @@
+--- a/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.cpp
++++ b/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.cpp
+@@ -1250,7 +1250,7 @@ CHECK_SIZE_AND_OFFSET(group, gr_passwd);
+ CHECK_SIZE_AND_OFFSET(group, gr_gid);
+ CHECK_SIZE_AND_OFFSET(group, gr_mem);
+ 
+-#if HAVE_RPC_XDR_H
++#if HAVE_RPC_XDR_H && !SANITIZER_MAC
+ CHECK_TYPE_SIZE(XDR);
+ CHECK_SIZE_AND_OFFSET(XDR, x_op);
+ CHECK_SIZE_AND_OFFSET(XDR, x_ops);