tcl @8.6.10_0 +corefoundation +threads : configure tests failing with "implicitly declaring ... function" error

[lmhaffner]

A number of tests in configure are failing as this warning seems to have been elevated to an error in macOS 11.x/XCode 12.3(?). One example from the attached config.log:

conftest.c:26:7: error: implicitly declaring library function 'exit' with type 'void (int) __attribute__((noreturn))' [-Werror,-Wimp
licit-function-declaration]
      exit(2);
      ^
conftest.c:26:7: note: include the header <stdlib.h> or explicitly provide a declaration for 'exit'
1 error generated.

In some cases, this prevents an expected success (e.g., strtoul implementation testing) and is leading to odd errors downstream (e.g., tclx compilation failing due to a missing symbol in libtclstub8.6.a).

[lmhaffner]

config.log

[jmroot (Joshua Root)]

Cf. ​https://github.com/macports/macports-base/blob/master/vendor/patches/tcl/configure-implicit-declarations.patch

I wasn't sure how much of that also applied to 8.6.10.

[jmroot (Joshua Root)]

In 923068766f9d3f56473e545d882f9c70ca7c5684/macports-ports (master):

tcl: fix implicit declarations in configure

Rev bump due to different resulting configuration.

Closes: #61897