Specify output explicitly for the .c.o compile rule

The current Makefile.in does not specify the output file name even though upper
level Makefile assumes that the output filename is crt0.o. However, breaks when
the compiler does not use .o extension for object files. Newer Automake is
already using explicit output, but since Newlib does not currently build with
newer Autoconf/Automake versions, we need to override the rule manually.

BUG= none
TEST= toolchain_build_pnacl.py
R=mcgrathr@chromium.org

Review URL: https://codereview.chromium.org/1377003003 .
2 files changed