Bug 1720606 - Fix for clang-trunk build after IR commit broken the at…

…tributes patch. r=firefox-build-system-reviewers,glandium

After changeset 5e4b33fe9218703f0b29e2446159bcf4202d15fa the Attributes.cpp file was
changed so our patched version was not sticking on top of it. This patch does the proper
rebase.

Differential Revision: https://phabricator.services.mozilla.com/D119951

build/build-clang/clang-trunk-linux64.json

@@ -16,7 +16,7 @@
     "android-mangling-error_clang_12.patch",
     "unpoison-thread-stacks_clang_10.patch",
     "downgrade-mangling-error_clang_12.patch",
-    "revert-llvmorg-12-init-7827-g2a078c307204.patch",
+    "revert-llvmorg-12-init-7827-g2a078c307204-trunk.patch",
     "loosen-msvc-detection.patch"
   ]
 }

build/build-clang/revert-llvmorg-12-init-7827-g2a078c307204-trunk.patch

@@ -0,0 +1,12 @@
+diff --git a/llvm/lib/IR/Attributes.cpp b/llvm/lib/IR/Attributes.cpp
+index 368fc87dc801..96c2388d776e 100644
+--- a/llvm/lib/IR/Attributes.cpp
++++ b/llvm/lib/IR/Attributes.cpp
+@@ -1902,7 +1902,6 @@ AttrBuilder AttributeFuncs::typeIncompatible(Type *Ty) {
+         .addAttribute(Attribute::ReadNone)
+         .addAttribute(Attribute::ReadOnly)
+         .addAttribute(Attribute::SwiftError)
+-        .addAlignmentAttr(1)             // the int here is ignored
+         .addDereferenceableAttr(1)       // the int here is ignored
+         .addDereferenceableOrNullAttr(1) // the int here is ignored
+         .addPreallocatedAttr(Ty)