Add BPF target

This change adds the bpfel-unknown-none and bpfeb-unknown-none targets
which can be used to generate little endian and big endian BPF

compiler/rustc_llvm/build.rs

@@ -86,6 +86,7 @@ fn main() {
         "nvptx",
         "hexagon",
         "riscv",
+        "bpf",
     ];
 
     let required_components = &[

compiler/rustc_llvm/src/lib.rs

@@ -167,4 +167,12 @@ pub fn initialize_available_targets() {
         LLVMInitializeWebAssemblyAsmPrinter,
         LLVMInitializeWebAssemblyAsmParser
     );
+    init_target!(
+        llvm_component = "bpf",
+        LLVMInitializeBPFTargetInfo,
+        LLVMInitializeBPFTarget,
+        LLVMInitializeBPFTargetMC,
+        LLVMInitializeBPFAsmPrinter,
+        LLVMInitializeBPFAsmParser
+    );
 }