Ensure gotox to be the start of the asm insn.

  Also remove gotol to be in the middle of asm insn.

Author: Yonghong Song

llvm/lib/Target/BPF/AsmParser/BPFAsmParser.cpp

@@ -232,6 +232,7 @@ struct BPFOperand : public MCParsedAsmOperand {
         .Case("callx", true)
         .Case("goto", true)
         .Case("gotol", true)
+        .Case("gotox", true)
         .Case("may_goto", true)
         .Case("*", true)
         .Case("exit", true)
@@ -261,7 +262,6 @@ struct BPFOperand : public MCParsedAsmOperand {
         .Case("bswap32", true)
         .Case("bswap64", true)
         .Case("goto", true)
-        .Case("gotol", true)
         .Case("ll", true)
         .Case("skb", true)
         .Case("s", true)