Add support for bf16 linkage

Author: sayantn

compiler/rustc_codegen_llvm/src/abi.rs

@@ -439,6 +439,17 @@ impl<'ll, 'tcx> FnAbiLlvmExt<'ll, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
                             false
                         }
                     }
+                    TypeKind::BFloat => rust_ty == cx.type_i16(),
+                    TypeKind::Vector => {
+                        let element_count = cx.vector_length(llvm_ty);
+                        let element_ty = cx.element_type(llvm_ty);
+
+                        if element_ty == cx.type_bf16() {
+                            rust_ty == cx.type_vector(cx.type_i16(), element_count as u64)
+                        } else {
+                            false
+                        }
+                    }
                     _ => false,
                 }
             };