Optimization/link problem at gcc -O1

This fails on MinGW GCC 3.4.1 RC, as well as vanilla FSF
GCC 3.4.0 and FSF GCC head.

It's not a minimal testcase, and not even proper C, and
I have not done too much past this to analyze the
failure beyond get this testcase. I'm sort of frazzled at
the moment.

ixx reported that this causing build failures in dna
analysis tool. a websearch indicates that this may be
causing failures in quite a few other programs also. the
code itself is distilled from mingwrt head.

This fails with:
gcc -O1 -shared p.c -o p.dll
but not with:
gcc -O1 -shared p.c -o p.dll

Errors:
Info: resolving ___mb_cur_max by linking to
__imp____mb_cur_max (auto-import)
Info: resolving __pctype by linking to __imp___pctype
(auto-import)
fu000001.o(.idata$3+0xc): undefined reference to
`libmsvcrt_a_iname'
fu000003.o(.idata$3+0xc): undefined reference to
`libmsvcrt_a_iname'
nmth000000.o(.idata$4+0x0): undefined reference to
`_nm____mb_cur_max'
nmth000002.o(.idata$4+0x0): undefined reference to
`_nm___pctype'

Testcase:

extern int __mb_cur_max;
extern unsigned short* _pctype;

extern __inline__ int isdigit(int c) {
return (__mb_cur_max == 1 ? (_pctype[c] & 0x0004)
: _isctype(c, 0x0004));
}

extern __inline__ int isspace(int c) {
return (__mb_cur_max == 1 ? (_pctype[c] & 0x0008)
: _isctype(c, 0x0008));
}

int llama() {
if (!isdigit(0) && isspace(0))
return 1;

return 0;
}