https://bugs.gentoo.org/937525
https://bugs.gentoo.org/937164

Unnecessary on 19+ because 2222fddfc0a2ff02036542511597839856289094 adds
SmallVector and SmallVector is fixed by another patch.
--- a/src/llvm-project/llvm/lib/Target/X86/MCTargetDesc/X86MCTargetDesc.h
+++ b/src/llvm-project/llvm/lib/Target/X86/MCTargetDesc/X86MCTargetDesc.h
@@ -13,6 +13,7 @@
 #ifndef LLVM_LIB_TARGET_X86_MCTARGETDESC_X86MCTARGETDESC_H
 #define LLVM_LIB_TARGET_X86_MCTARGETDESC_X86MCTARGETDESC_H
 
+#include <cstdint>
 #include <memory>
 #include <string>