sync: latest libbpf changes from kernel

Syncing latest libbpf commits from kernel repository.
Baseline bpf-next commit:   3c4f850e8441ac8b3b6dbaa6107604c4199ef01f
Checkpoint bpf-next commit: bfdd5aaa54b0a44d9df550fe4c9db7e1470a11b8
Baseline bpf commit:        5b801dfb7feb2738975d80223efc2fc193e55573
Checkpoint bpf commit:      929e54a989680c6f134b02293732030b897475dc

Andrii Nakryiko (3):
  libbpf: Make destructors more robust by handling ERR_PTR(err) cases
  libbpf: Add bpf_link detach APIs
  libbpf: Add btf__parse_raw() and generic btf__parse() APIs

Daniel T. Lee (1):
  libbf: Fix uninitialized pointer at btf__parse_raw()

Jerry Crunchtime (1):
  libbpf: Fix register in PT_REGS MIPS macros

Yonghong Song (1):
  tools/bpf: Support new uapi for map element bpf iterator

 include/uapi/linux/bpf.h |  20 ++++---
 src/bpf.c                |  13 +++++
 src/bpf.h                |   7 ++-
 src/bpf_tracing.h        |   4 +-
 src/btf.c                | 118 ++++++++++++++++++++++++++-------------
 src/btf.h                |   5 +-
 src/btf_dump.c           |   2 +-
 src/libbpf.c             |  20 ++++---
 src/libbpf.h             |   6 +-
 src/libbpf.map           |   4 ++
 10 files changed, 137 insertions(+), 62 deletions(-)

--
2.24.1

BPF-CHECKPOINT-COMMIT

@@ -1 +1 @@
-5b801dfb7feb2738975d80223efc2fc193e55573
+929e54a989680c6f134b02293732030b897475dc

CHECKPOINT-COMMIT

@@ -1 +1 @@
-3c4f850e8441ac8b3b6dbaa6107604c4199ef01f
+bfdd5aaa54b0a44d9df550fe4c9db7e1470a11b8