Nuke the old JIT.

I am sure we will be finding bits and pieces of dead code for years to
come, but this is a good start.

Thanks to Lang Hames for making MCJIT a good replacement!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215111 91177308-0d34-0410-b5e6-96231b3b80d8

test/ExecutionEngine/MCJIT/test-ret.ll

@@ -1,4 +1,4 @@
-; RUN: %lli_mcjit %s > /dev/null
+; RUN: %lli %s > /dev/null
 
 ; test return instructions
 define void @test1() {