Check config.log for -Wimplicit-int and -Wincompatible-function-pointer-types

[ryandesign (Ryan Carsten Schmidt)]

MacPorts base contains code that checks config.log files for instances of implicit function declarations because new clang versions default to -Werror=implicit-function-declaration and this can cause available features not to be found:

​https://github.com/macports/macports-base/blob/4dfabb9c0de9abfcbb4acf1ad68471b0a20983ab/src/port1.0/portconfigure.tcl#L1910-L1955

Even newer clang versions default to -Werror=implicit-int and -Werror=incompatible-function-pointer-types. Shall MacPorts base be enhanced to check for and warn about these too? I just encountered a port (php74) that failed to build due to an incorrect configure decision resulting from implicit int.

[ryandesign (Ryan Carsten Schmidt)]

​https://github.com/macports/macports-base/pull/331