Extend ifelse lifting to regular SROA (JuliaLang#50403)

* Extend ifelse lifting to regular SROA

* Fix oracle violation

This is a pre-existing bug, but was exposed by my improvements to
SROA.

base/compiler/ssair/ir.jl

@@ -879,6 +879,9 @@ function insert_node!(compact::IncrementalCompact, @nospecialize(before), newins
             return os
         end
     elseif isa(before, NewSSAValue)
+        # As above, new_new_nodes must get counted. We don't visit them during our compact,
+        # so they're immediately considered reified.
+        count_added_node!(compact, newinst.stmt)
         # TODO: This is incorrect and does not maintain ordering among the new nodes
         before_entry = compact.new_new_nodes.info[-before.id]
         newline = something(newinst.line, compact.new_new_nodes.stmts[-before.id][:line])

base/compiler/ssair/passes.jl

@@ -563,6 +563,12 @@ function lift_comparison!(::typeof(isdefined), compact::IncrementalCompact,
     lift_comparison_leaves!(isdefined_tfunc, compact, val, cmp, lifting_cache, idx, 𝕃ₒ)
 end
 
+function phi_or_ifelse_predecessors(@nospecialize(def), compact::IncrementalCompact)
+    isa(def, PhiNode) && return def.values
+    is_known_call(def, Core.ifelse, compact) && return def.args[3:4]
+    return nothing
+end
+
 function lift_comparison_leaves!(@specialize(tfunc),
     compact::IncrementalCompact, @nospecialize(val), @nospecialize(cmp),
     lifting_cache::IdDict{Pair{AnySSAValue, Any}, AnySSAValue}, idx::Int,
@@ -573,12 +579,8 @@ function lift_comparison_leaves!(@specialize(tfunc),
     end
     isa(typeconstraint, Union) || return # bail out if there won't be a good chance for lifting
 
-    predecessors = function (@nospecialize(def), compact::IncrementalCompact)
-        isa(def, PhiNode) && return def.values
-        is_known_call(def, Core.ifelse, compact) && return def.args[3:4]
-        return nothing
-    end
-    leaves, visited_philikes = collect_leaves(compact, val, typeconstraint, 𝕃ₒ, predecessors)
+
+    leaves, visited_philikes = collect_leaves(compact, val, typeconstraint, 𝕃ₒ, phi_or_ifelse_predecessors)
     length(leaves) ≤ 1 && return # bail out if we don't have multiple leaves
 
     # check if we can evaluate the comparison for each one of the leaves
@@ -1093,11 +1095,10 @@ function sroa_pass!(ir::IRCode, inlining::Union{Nothing,InliningState}=nothing)
         end
 
         # perform SROA on immutable structs here on
-
         field = try_compute_fieldidx_stmt(compact, stmt, struct_typ)
         field === nothing && continue
 
-        leaves, visited_philikes = collect_leaves(compact, val, struct_typ, 𝕃ₒ)
+        leaves, visited_philikes = collect_leaves(compact, val, struct_typ, 𝕃ₒ, phi_or_ifelse_predecessors)
         isempty(leaves) && continue
 
         lifted_result = lift_leaves(compact, field, leaves, 𝕃ₒ)