chore: disable most LCNF passes to be able to use update-stage0

We cannot effectively test without an `update-stage0` since the LCNF
representation is different and incompatible with the one in the
.olean files.

One of the passes is not terminating (probably `simp`) when compiling
stage2.

src/Lean/Compiler/LCNF/Passes.lean

@@ -45,6 +45,7 @@ def builtinPassManager : PassManager := {
     init,
     pullInstances,
     cse,
+/-
     simp,
     floatLetIn,
     findJoinPoints,
@@ -55,7 +56,9 @@ def builtinPassManager : PassManager := {
     specialize,
     simp (occurrence := 2),
     cse (occurrence := 1),
+-/
     saveBase, -- End of base phase
+/-
     toMono,
     simp (occurrence := 3) (phase := .mono),
     reduceJpArity (phase := .mono),
@@ -69,6 +72,7 @@ def builtinPassManager : PassManager := {
     extendJoinPointContext (phase := .mono) (occurrence := 1),
     simp (occurrence := 5) (phase := .mono),
     cse (occurrence := 2) (phase := .mono),
+-/
     saveMono  -- End of mono phase
   ]
 }