Merge bitcoin/bitcoin#27462: depends: fix compiling bdb with clang-16 on aarch64

f8b8458 depends: fix compiling bdb with clang-16 on aarch64 (fanquake)

Pull request description:

  Compiling bdb with clang-16 on aarch64 (hardware) currently fails:
  ```bash
  make -C depends/ bdb CC=clang CXX=clang++
  ...
  checking for mutexes... UNIX/fcntl
  configure: WARNING: NO SHARED LATCH IMPLEMENTATION FOUND FOR THIS PLATFORM.
  configure: error: Unable to find a mutex implementation
  ```

  Looking at config.log we've got:
  ```bash
  configure:18704: checking for mutexes
  configure:18815: clang -o conftest -pipe -std=c11 -O2 -Wno-error=implicit-function-declaration -Wno-error=format-security    -I/bitcoin/depends/aarch64-unknown-linux-gnu/include -D_GNU_SOURCE -D_REENTRANT   -L/bitcoin/depends/aarch64-unknown-linux-gnu/lib conftest.c  -lpthread >&5
  conftest.c:45:1: error: type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
  main() {
  ^
  int
  conftest.c:50:2: warning: call to undeclared library function 'exit' with type 'void (int) __attribute__((noreturn))'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
          exit (
          ^
  conftest.c:50:2: note: include the header <stdlib.h> or explicitly provide a declaration for 'exit'
  1 warning and 1 error generated.
  ```

  Clang-16 changed `-Wimplicit-function-declaration` and `-Wimplicit-int`
  warnings into errors, see:
  https://releases.llvm.org/16.0.0/tools/clang/docs/ReleaseNotes.html#potentially-breaking-changes.

  > The -Wimplicit-function-declaration and -Wimplicit-int warnings now
  > default to an error in C99, C11, and C17. As of C2x, support for implicit
  > function declarations and implicit int has been removed, and the
  > warning options will have no effect. Specifying -Wimplicit-int in
  > C89 mode will now issue warnings instead of being a noop.

ACKs for top commit:
  hebasto:
    ACK f8b8458, tested on Ubuntu Lunar (`aarch64`) with:

Tree-SHA512: 5ca078b1c00915446e9f0f2ecaa4342295a2097996554345753315d1c81c23000c57be14e1ac5506a87820f5114aba748456f2c2b6426b0810504d62d761a787

Author: fanquake

depends/packages/bdb.mk

@@ -14,7 +14,7 @@ $(package)_config_opts_freebsd=--with-pic
 $(package)_config_opts_netbsd=--with-pic
 $(package)_config_opts_openbsd=--with-pic
 $(package)_config_opts_android=--with-pic
-$(package)_cflags+=-Wno-error=implicit-function-declaration -Wno-error=format-security
+$(package)_cflags+=-Wno-error=implicit-function-declaration -Wno-error=format-security -Wno-error=implicit-int
 $(package)_cppflags_freebsd=-D_XOPEN_SOURCE=600 -D__BSD_VISIBLE=1
 $(package)_cppflags_netbsd=-D_XOPEN_SOURCE=600
 $(package)_cppflags_openbsd=-D_XOPEN_SOURCE=600