Revert "hipe: Remove single function compilation"

This reverts commit 0aa3a8200025ae32c5aba11be5229fff19d03c7f.
First commit to llvm/.
Added hipe_rtl2llvm.erl (foo-file) to work with main/hipe_main.erl.
hipe_rtl2llvm: parse RTL and write to file

Created Makefile for llvm/ and updated hipe/ main Makefile (XXX: Is this
correct?). Linked llvm/hipe_rtl2llvm.erl to main/hipe_main.erl.
hipe_rtl2llvm:translate/1: print RTL to file
Added translation of call,return,move,label,goto

Changed rtl/hipe_rtl.erl to export pp_var/2, pp_arg/2.
Maybe wrap llvm instructions to another module?
Added translation of branch,alu and fun header
Improved creation of main function
Some code cleanup and typos correction

Still need to remove some 'catch all' clauses in trans_arg.
Created testsuite
Added placeholders for all rtl instructions.

Changed function order to match with rtl/hipe_rtl.hrl
Added flag [to_llvm] to HiPe compiler

When set, this flag creates two files: one for RTL code (<F>.rtl) and one for
LLVM assembly code (<F>.ll) for each function compiled.
Also, changed Makefile in test suite to remove those files with "make clean".
Added translation of alub and phi rtl instructions
Added flag [to_llvm] to HiPe compiler

When set, this flag creates two files: one for RTL code (<F>.rtl) and one for
LLVM assembly code (<F>.ll) for each function compiled.
Also, changed Makefile in test suite to remove those files with "make clean".
Trivial refactor in main/hipe_main.erl
Linearized RTL-SSA form before translating to llvm

Fixed identation in phi node.
Hacked hipe_gensym to support LLVM counter
Added translation of comment, gctest, fixnumop
Added new testcase for tuples
Created abstraction level for llvm assembly instrs
Changed from atoms to strings

hipe_llvm.erl will use strings instead of atoms