Bump external/ebpf-verifier from df34181 to 2018df9 (#3600)

* Bump external/ebpf-verifier from `df34181` to `2018df9`

Bumps [external/ebpf-verifier](https://github.com/vbpf/ebpf-verifier) from `df34181` to `2018df9`.
- [Release notes](https://github.com/vbpf/ebpf-verifier/releases)
- [Commits](vbpf/prevail@df34181...2018df9)

---
updated-dependencies:
- dependency-name: external/ebpf-verifier
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

* Fix build failures due to breaking change

Signed-off-by: Dave Thaler <dthaler1968@gmail.com>

---------

Signed-off-by: dependabot[bot] <support@github.com>
Signed-off-by: Dave Thaler <dthaler1968@gmail.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Dave Thaler <dthaler1968@gmail.com>

Author: dependabot[bot]

external/ebpf-verifier

@@ -683,7 +683,7 @@ _ebpf_api_elf_verify_program_from_stream(
         }
         auto& program = std::get<InstructionSeq>(programOrError);
 
-        verifier_options.no_simplify = true;
+        verifier_options.simplify = false;
         bool res =
             ebpf_verify_program(output, program, raw_program.info, &verifier_options, (ebpf_verifier_stats_t*)stats);
         if (!res) {

libs/api/Verifier.cpp

@@ -32,7 +32,7 @@ _analyze(raw_program& raw_prog, const char** error_message, uint32_t* error_mess
     if (!res) {
         // On failure, retry to get the more detailed error message.
         std::ostringstream oss;
-        options.no_simplify = true;
+        options.simplify = false;
         options.print_failures = true;
         // Until https://github.com/vbpf/ebpf-verifier/issues/643 is fixed, don't set options.assume_assertions to true.
         (void)ebpf_verify_program(oss, prog, raw_prog.info, &options, &stats);