perf srcline: Fallback between addr2line implementations

perf srcline: Fallback between addr2line implementations

Factor the addr2line function implementation into separate source files
(addr2line.[ch]) and rename the addr2line function cmd__addr2line. In
srcline replace the ifdef-ed addr2line implementations with one that
first tries the llvm__addr2line implementation, then the deprecated
libbfd__addr2line function and on failure uses cmd__addr2line.

If HAVE_LIBLLVM_SUPPORT is enabled the llvm__addr2line will execute
against the libLLVM.so it is linked against.

If HAVE_LIBLLVM_DYNAMIC is enabled then libperf-llvm.so (that links
against libLLVM.so) will be dlopened. If the dlopen succeeds then the
behavior should match HAVE_LIBLLVM_SUPPORT. On failure cmd__addr2line is
used. The dlopen is only tried once.

If HAVE_LIBLLVM_DYNAMIC isn't enabled then llvm__addr2line immediately
fails and cmd__addr2line is used.

Clean up the dso__free_a2l logic, which is only needed in the non-LLVM
version and moved to addr2line.c.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.ibm.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Charlie Jenkins <charlie@rivosinc.com>
Cc: Collin Funk <collin.funk1@gmail.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Dr. David Alan Gilbert <linux@treblig.org>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Haibo Xu <haibo1.xu@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Li Huafei <lihuafei1@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <nick.desaulniers+lkml@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: Stephen Brennan <stephen.s.brennan@oracle.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>