Revert "Fix PR 24415 (at least), by making our post-dominator tree behavior sane."

and also "clang-format GenericDomTreeConstruction.h, since the current
formatting makes it look like their is a bug in the loop indentation, and there
is not"

This reverts commit r296535.

There are still some open design questions which I would like to discuss. I
revert this for Daniel (who gave the OK), as he is on vacation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296812 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/StructurizeCFG/branch-on-argument.ll

@@ -3,17 +3,14 @@
 ; CHECK-LABEL: @invert_branch_on_arg_inf_loop(
 ; CHECK: entry:
 ; CHECK: %arg.inv = xor i1 %arg, true
+; CHECK: phi i1 [ false, %Flow1 ], [ %arg.inv, %entry ]
 define void @invert_branch_on_arg_inf_loop(i32 addrspace(1)* %out, i1 %arg) {
 entry:
-  br i1 %arg, label %for.end, label %sesestart
-sesestart:
-  br label %for.body
+  br i1 %arg, label %for.end, label %for.body
 
 for.body:                                         ; preds = %entry, %for.body
   store i32 999, i32 addrspace(1)* %out, align 4
-  br i1 %arg, label %for.body, label %seseend
-seseend:
-  ret void
+  br label %for.body
 
 for.end:                                          ; preds = %Flow
   ret void

test/Transforms/StructurizeCFG/no-branch-to-entry.ll

@@ -1,4 +1,3 @@
-; XFAIL: *
 ; RUN: opt -S -o - -structurizecfg -verify-dom-info < %s | FileCheck %s
 
 ; CHECK-LABEL: @no_branch_to_entry_undef(