[bug-gawk] Call from BEGIN to user-defined function with explicit return causes SIGSEGV in Gawk 3.1.6 Win32

[Developer Address]

The following script terminates with a SIGSEGV error when executed on Gawk 3.1.6.2962 Win32:

BEGIN {
    a();
}

function a() {
    return 0;
}

No input file is used. Command and output are:

----
E:\gawk-issue>.\gawk.exe -f breakIt.awk
gawk: breakIt.awk:7: fatal error: internal error (SIGSEGV)

This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.
----

The issue is not present in 3.1.4. Additionally:

- The value of the return statement is immaterial
- Issue propagates through multiple calls; for example, if BEGIN calls a() and a() has no explicit return but calls b(), which does have an explicit return, problem occurs
- Implicit return (for instance, empty a() function body) not affected
- Line endings (Unix vs. DOS) immaterial

System is Windows XP SP3 on Core2 Duo w/PAE. DLLs are:

libintl3.dll: 0.14.1.1737
libiconv2.dll: 1.9.2.1519

Please advise of any need for additional information. Thanks!