* alpha.h (CPP_PREDEFINES, LIB_SPEC, LINK_SPEC, STARTFILE_SPEC,
MD_STARTFILE_PREFIX, ASM_FILE_START, ASM_SPEC, ASM_FINAL_SPEC):
Move OSF/1 specific defines out.
* alpha/elf.h (TARGET_VERSION, CPP_PREDEFINES, DEFAULT_VTABLE_THUNKS):
Move Linux specific defines out.
(LINK_SPEC): Genericize.
(ASM_FILE_START): Emit .arch if using more than the base insn set.
(ASM_OUTPUT_SOURCE_LINE): Remove; identical to alpha.h version.
(SDB_DEBUGGING_INFO): Remove; gas can't handle it.
(HANDLE_SYSV_PRAGMA): Define.
* alpha/osf.h: New file.
* alpha/linux.h: Split.  Retain file-format independant defines.
Import Linux bits from elf.h.
(CPP_PREDEFINES): Take a file-format specific SUB_CPP_PREDEFINES
(FUNCTION_PROFILER): _mcount takes its address in $28.
(MD_EXEC_PREFIX, MD_STARTFILE_PREFIX): Remove undef.
* alpha/linux-ecoff.h: New file.
* alpha/linux-elf.h: New file.
* alpha/vms.h (LIB_SPEC, LINK_SPEC): Copy from osf.h.
* alpha/win-nt.h (TARGET_DEFAULT): Define.
* configure.in (alpha*-*-osf*, alpha*-*-linux*) [tm_file]:
Add new headers as appropriate.
* configure.in (alpha*): Enable Haifa by default.
(*-*-winnt3*): Change to winnt*, since we're not v3 specific.
* configure: Rebuild.

From-SVN: r17211