Linker emulation selection

A linker emulation is a “personality” of the linker; it gives the linker default values for the other aspects of the target system. In particular, it consists of the linker script, the target, and several “hook” functions that are run at certain stages of the linking process to do special things that some targets require.

The command to list valid linker emulation values is ld -V. Sample values include i386nto.

Ways to specify:

1. -m command-line option
2. LDEMULATION environment variable
3. Compiled-in DEFAULT_EMULATION from Makefile, which comes from EMUL in config/target.mt.