[v3] use AM_ICONV

[Benjamin Kosnik]

> I don't think libstdc++-v3 should fail to configure because I didn't
> specify --with-newlib.  In particular I don't think it should fail to
> configure with a meaningless error message.

There are other cross libc's now.

> I just confirmed that it fails with
> 
> appending configuration tag "CXX" to libtool
> checking for ld used by GCC... /home/iant/gcc/m32c-elf/./gcc/collect-ld
> checking if the linker (/home/iant/gcc/m32c-elf/./gcc/collect-ld) is GNU ld... yes
> checking for shared library run path origin... done
> checking for iconv... configure: error: Link tests are not allowed after GCC_NO_EXECUTABLES.
> make: *** [configure-target-libstdc++-v3] Error 1

... but does not when the config is:


$src/gcc.combined/configure --prefix=$bld/H-x86-x-m32c-elf-gcc 
--enable-languages=c,c++ --enable-__cxa_atexit --disable-checking 
--with-newlib --disable-gdbtk --target=m32c-elf

which happily goes until:

/mnt/share/bld/gcc.x86-x-m32c-elf/./gcc/xgcc -shared-libgcc 
-B/mnt/share/bld/gcc.x86-x-m32c-elf/./gcc -nostdinc++ 
-L/mnt/share/bld/gcc.x86-x-m32c-elf/m32c-elf/m32cm/libstdc++-v3/src 
-L/mnt/share/bld/gcc.x86-x-m32c-elf/m32c-elf/m32cm/libstdc++-v3/src/.libs 
-nostdinc -B/mnt/share/bld/gcc.x86-x-m32c-elf/m32c-elf/m32cm/newlib/ 
-isystem 
/mnt/share/bld/gcc.x86-x-m32c-elf/m32c-elf/m32cm/newlib/targ-include 
-isystem /mnt/share/src/gcc.combined/newlib/libc/include 
-B/mnt/share/bld/H-x86-x-m32c-elf-gcc/m32c-elf/bin/ 
-B/mnt/share/bld/H-x86-x-m32c-elf-gcc/m32c-elf/lib/ -isystem 
/mnt/share/bld/H-x86-x-m32c-elf-gcc/m32c-elf/include -isystem 
/mnt/share/bld/H-x86-x-m32c-elf-gcc/m32c-elf/sys-include 
-L/mnt/share/bld/gcc.x86-x-m32c-elf/./ld 
-B/mnt/share/bld/gcc.x86-x-m32c-elf/m32c-elf/m32cm/libgloss/m32c 
-L/mnt/share/bld/gcc.x86-x-m32c-elf/m32c-elf/m32cm/libgloss/m32c 
-L/mnt/share/bld/gcc.x86-x-m32c-elf/m32c-elf/m32cm/libgloss/libnosys 
-mcpu=m32cm 
-I/mnt/share/bld/gcc.x86-x-m32c-elf/m32c-elf/m32cm/libstdc++-v3/include/m32c-elf 
-I/mnt/share/bld/gcc.x86-x-m32c-elf/m32c-elf/m32cm/libstdc++-v3/include 
-I/mnt/share/src/gcc.combined/libstdc++-v3/libsupc++ 
-fno-implicit-templates -Wall -Wextra -Wwrite-strings -Wcast-qual 
-fdiagnostics-show-location=once -ffunction-sections -fdata-sections -g 
-O2 -mcpu=m32cm -c 
/mnt/share/src/gcc.combined/libstdc++-v3/src/fstream-inst.cc -o 
fstream-inst.o
/mnt/share/bld/gcc.x86-x-m32c-elf/m32c-elf/m32cm/libstdc++-v3/include/bits/fstream.tcc: 
In member function 'typename std::basic_filebuf<_CharT, 
_Traits>::pos_type std::basic_filebuf<_CharT, _Traits>::seekpos(typename 
_Traits::pos_type, std::_Ios_Openmode) [with _CharT = char, _Traits = 
std::char_traits<char>]':
/mnt/share/bld/gcc.x86-x-m32c-elf/m32c-elf/m32cm/libstdc++-v3/include/bits/fstream.tcc:730: 
error: insn does not satisfy its constraints:
(insn 183 180 182 10 
/mnt/share/bld/gcc.x86-x-m32c-elf/m32c-elf/m32cm/libstdc++-v3/include/bits/fstream.tcc:728 
(set (reg:HI 2 r1)
         (reg:HI 8 sp)) 171 {movhi_op} (nil)
     (nil))
/mnt/share/bld/gcc.x86-x-m32c-elf/m32c-elf/m32cm/libstdc++-v3/include/bits/fstream.tcc:730: 
internal compiler error: in reload_cse_simplify_operands, at 
postreload.c:393
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.
make[8]: *** [fstream-inst.lo] Error 1
make[8]: Leaving directory 
`/mnt/share/bld/gcc.x86-x-m32c-elf/m32c-elf/m32cm/libstdc++-v3/src'


-benjamin