[ARM64] [Windows] Mark block address as taken when expanding catchrets

This fixes issue llvm#109250

The issue happens during the `MachineBlockPlacement` pass.
The block, whose address was previously not taken, is deemed redundant
by the pass and subsequently replaced using
`MachineBasicBlock::ReplaceUsesOfBlockWith` in `BranchFolding`.

ReplaceUsesOfBlockWith only replaces uses in the terminator.
However, `expandPostRAPseudo` introduces new block uses
when expanding catchrets. These uses do not get replaced, which results
in undefined label errors later on.

Marking the block addresss as taken prevents the replacement of the block,
without also replacing non-terminator uses.

llvm/lib/Target/AArch64/AArch64InstrInfo.cpp

@@ -1994,6 +1994,7 @@ bool AArch64InstrInfo::expandPostRAPseudo(MachineInstr &MI) const {
         .addReg(AArch64::X0)
         .addMBB(TargetMBB)
         .addImm(0);
+    TargetMBB->setMachineBlockAddressTaken();
     return true;
   }
 

llvm/test/CodeGen/AArch64/pr58516.ll

@@ -40,7 +40,8 @@ define void @osfx(ptr %this) comdat personality ptr @__CxxFrameHandler3 {
 ; CHECK-NEXT:  // %bb.1: // %invoke.cont12
 ; CHECK-NEXT:    str wzr, [x20]
 ; CHECK-NEXT:    str wzr, [x21]
-; CHECK-NEXT:  .LBB0_2: // %try.cont
+; CHECK-NEXT:  .LBB0_2: // Block address taken
+; CHECK-NEXT:    // %try.cont
 ; CHECK-NEXT:  $ehgcr_0_2:
 ; CHECK-NEXT:    .seh_startepilogue
 ; CHECK-NEXT:    sub sp, x29, #24

llvm/test/CodeGen/AArch64/wineh-catchret-obj-generation.ll

@@ -0,0 +1,45 @@
+; RUN: llc -mtriple aarch64-unknown-windows-msvc -filetype=obj %s -o %t.o
+
+declare i32 @__CxxFrameHandler3(...)
+
+declare void @llvm.seh.try.begin() #0
+
+define fastcc ptr @test_function(i1 %0, ptr %_Fmtfl.i.i, i1 %1) personality ptr @__CxxFrameHandler3 {
+entry:
+  br i1 %0, label %right-block527, label %left-block526
+
+common.ret1:
+  %common.ret1.op = phi ptr [ null, %left-block530 ], [ null, %some-block ], [ %_Fmtfl.i.i, %invoke.cont.i124 ], [ null, %left-block526 ]
+  ret ptr %common.ret1.op
+
+invoke.cont.i124:
+  %.not657 = icmp eq i32 1, 0
+  br i1 %.not657, label %some-block, label %common.ret1
+
+catch.dispatch.i:
+  %2 = catchswitch within none [label %catch.i] unwind to caller
+
+catch.i:
+  %3 = catchpad within %2 [ptr null, i32 0, ptr null]
+  catchret from %3 to label %some-block
+
+some-block:
+  br label %common.ret1
+
+left-block526:
+  br i1 %1, label %common.ret1, label %left-block530
+
+right-block527:
+  invoke void @llvm.seh.try.begin()
+          to label %invoke.cont.i124 unwind label %catch.dispatch.i
+
+left-block530:
+  %.not = icmp eq i32 0, 0
+  br label %common.ret1
+}
+
+attributes #0 = { nounwind willreturn memory(write) }
+
+!llvm.module.flags = !{!0}
+
+!0 = !{i32 2, !"eh-asynch", i32 1}

llvm/test/CodeGen/AArch64/wineh-try-catch.ll

@@ -41,7 +41,7 @@
 ; CHECK-LABEL: .Ltmp0:
 ; CHECK:       bl      "?func2@@YAHXZ
 
-; CHECK:        [[CATCHRETDEST:.LBB0_[0-9]+]]:      // %catchret.dest
+; CHECK:        [[CATCHRETDEST:.LBB0_[0-9]+]]:      // Block address taken
 
 ; Check the catch funclet.
 ; CHECK-LABEL: "?catch$4@?0??func@@YAHXZ@4HA":