[SEH] Add test to track EHa register liveness verification (#76921)

This test tracks bug of MachineVerifier to check live range segment for
EHa. Async exception can happen at any place within seh scope, not only
the call instruction. Need to teach MachineVerifier to know that.

llvm/test/CodeGen/X86/windows-seh-EHa-RegisterLiveness.ll

@@ -0,0 +1,66 @@
+; XFAIL: *
+; RUN: llc --verify-machineinstrs < %s
+source_filename = "test.cpp"
+target datalayout = "e-m:w-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-windows-msvc19.12.0"
+
+$"?test@Test@@Plugin@@Host@@@Z" = comdat any
+
+declare i32 @__CxxFrameHandler3(...)
+
+; Function Attrs: nounwind memory(none)
+declare void @llvm.seh.scope.begin() #1
+
+; Function Attrs: nobuiltin allocsize(0)
+declare ptr @"??2@Test@Z"(i64) #1
+
+; Function Attrs: nounwind memory(none)
+declare void @llvm.seh.scope.end() #0
+
+; Function Attrs: nobuiltin nounwind
+declare void @"??3@YAXPEAX@Z"(ptr) #2
+
+; Function Attrs: mustprogress uwtable
+define ptr @"?test@Test@@Plugin@@Host@@@Z"(ptr %this, ptr %host) #3 comdat align 2 personality ptr @__CxxFrameHandler3 {
+entry:
+  %host.addr = alloca ptr, align 8
+  %this.addr = alloca ptr, align 8
+  store ptr %host, ptr %host.addr, align 8
+  store ptr %this, ptr %this.addr, align 8
+  %this1 = load ptr, ptr %this.addr, align 8
+  %call = call noalias ptr @"??2@Test@Z"(i64 152) #5
+  invoke void @llvm.seh.scope.begin()
+          to label %invoke.cont unwind label %ehcleanup
+
+invoke.cont:                                      ; preds = %entry
+  %call3 = invoke ptr @"??Test@?A0x2749C4FD@@QEAA@Test@Test@@@Z"(ptr %call, ptr %this1)
+          to label %invoke.cont2 unwind label %ehcleanup
+
+invoke.cont2:                                     ; preds = %invoke.cont
+  invoke void @llvm.seh.scope.end()
+          to label %invoke.cont4 unwind label %ehcleanup
+
+invoke.cont4:                                     ; preds = %invoke.cont2
+  ret ptr %call
+
+ehcleanup:                                        ; preds = %invoke.cont2, %invoke.cont, %entry
+  %0 = cleanuppad within none []
+  call void @"??3@YAXPEAX@Z"(ptr %call) #6 [ "funclet"(token %0) ]
+  cleanupret from %0 unwind to caller
+}
+
+; Function Attrs: uwtable
+declare hidden ptr @"??Test@?A0x2749C4FD@@QEAA@Test@Test@@@Z"(ptr, ptr) #4 align 2
+
+attributes #0 = { nounwind memory(none) }
+attributes #1 = { nobuiltin allocsize(0) "target-cpu"="x86-64" "target-features"="+cmov,+crc32,+cx8,+fxsr,+mmx,+popcnt,+sse,+sse2,+sse3,+sse4.1,+sse4.2,+ssse3,+x87" "tune-cpu"="generic" }
+attributes #2 = { nobuiltin nounwind "target-cpu"="x86-64" "target-features"="+cmov,+crc32,+cx8,+fxsr,+mmx,+popcnt,+sse,+sse2,+sse3,+sse4.1,+sse4.2,+ssse3,+x87" "tune-cpu"="generic" }
+attributes #3 = { mustprogress uwtable "target-cpu"="x86-64" "target-features"="+cmov,+crc32,+cx8,+fxsr,+mmx,+popcnt,+sse,+sse2,+sse3,+sse4.1,+sse4.2,+ssse3,+x87" "tune-cpu"="generic" }
+attributes #4 = { uwtable "target-cpu"="x86-64" "target-features"="+cmov,+crc32,+cx8,+fxsr,+mmx,+popcnt,+sse,+sse2,+sse3,+sse4.1,+sse4.2,+ssse3,+x87" "tune-cpu"="generic" }
+attributes #5 = { builtin allocsize(0) }
+attributes #6 = { builtin nounwind }
+
+!llvm.module.flags = !{!1, !2}
+
+!1 = !{i32 2, !"eh-asynch", i32 1}
+!2 = !{i32 7, !"uwtable", i32 2}