include * elf/wasm32.h: New file to support wasm32 architecture.
bfd * cpu-wasm32.c: New file to support wasm32 architecture.
* elf32-wasm32.c: New file to support wasm32 architecture.
* Makefile.am: Add wasm32 architecture.
* archures.c: Likewise.
* config.bfd: Likewise.
* configure.ac: Likewise.
* targets.c: Likewise.