ruby26 @2.6.0: error: ‘for’ loop initial declaration used outside C99 mode

[ryandesign (Ryan Carsten Schmidt)]

​ruby26 fails to build with compilers that default to C89 mode:

addr2line.c:15: warning: unknown option after ‘#pragma GCC diagnostic’ kind
addr2line.c: In function ‘di_find_abbrev’:
addr2line.c:1210: error: ‘for’ loop initial declaration used outside C99 mode
addr2line.c: In function ‘debug_info_read’:
addr2line.c:1558: error: ‘for’ loop initial declaration used outside C99 mode
addr2line.c: In function ‘fill_lines’:
addr2line.c:1904: error: ‘for’ loop initial declaration used outside C99 mode
addr2line.c:1940: error: ‘for’ loop initial declaration used outside C99 mode
addr2line.c:1958: error: ‘for’ loop initial declaration used outside C99 mode
addr2line.c:1961: error: ‘for’ loop initial declaration used outside C99 mode
addr2line.c:1999: error: ‘for’ loop initial declaration used outside C99 mode
make: *** [addr2line.o] Error 1

[ken-cunningham-webuse]

In 2009a25766ee4df1946f83c9254e4e018b6dacdc/macports-ports (master):

ruby26: add fix for Tiger

add std=c99 where needed
and refactor legacy support to consolidate fixes
closes: #57985