fix for g++.pt/vaarg.C

[Brad Lucier]

I think that this fix 

        * alpha.c (alpha_build_va_list): Use make_lang_type and
        initialize TYPE_NAME for the va_list record.

may cause a bootstrap failure on alpha:

/export/u11/lucier/programs/egcs/objdir-test/gcc/xgcc -B/export/u11/lucier/programs/egcs/objdir-test/gcc/ -B/export/u10/egcs-test/alphaev6-unknown-linux-gnu/bin/ -c -g -O2 -fvtable-thunks -D_GNU_SOURCE -fno-implicit-templates -I. -I../../../libio -nostdinc++ -D_IO_MTSAFE_IO ../../../libio/isscan.cc
../../../libio/isscan.cc: In method `istream &istream::scan (const char *, ...)':
../../../libio/isscan.cc:36: could not convert `ap' to `__va_list_tag'
../../../libio/isscan.cc: In method `istream &istream::vscan (const char *, __va_list_tag)':
../../../libio/isscan.cc:50: could not convert `args' to `__va_list_tag'
make[2]: *** [isscan.o] Error 1

Brad Lucier