TailDuplication: Clear NoPHIs property

The early tail duplicator pass introduces new ones, so a MIR test that
infers no phis since there were none on the input would fail the
verifier after running.

llvm/lib/CodeGen/TailDuplication.cpp

@@ -60,6 +60,11 @@ public:
   EarlyTailDuplicate() : TailDuplicateBase(ID, true) {
     initializeEarlyTailDuplicatePass(*PassRegistry::getPassRegistry());
   }
+
+  MachineFunctionProperties getClearedProperties() const override {
+    return MachineFunctionProperties()
+      .set(MachineFunctionProperties::Property::NoPHIs);
+  }
 };
 
 } // end anonymous namespace

llvm/test/CodeGen/AMDGPU/early-tailduplicator-nophis.mir

@@ -0,0 +1,41 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -run-pass=early-tailduplication -verify-machineinstrs -o - %s | FileCheck %s
+
+ # There are no phis in this testcase. Early tail duplication introduces them,
+ # so the NoPHIs property needs to be cleared to avoid verifier errors
+
+---
+name:           tail_duplicate_nophis
+tracksRegLiveness: true
+body:             |
+  ; CHECK-LABEL: name: tail_duplicate_nophis
+  ; CHECK: bb.0:
+  ; CHECK:   successors: %bb.3(0x80000000)
+  ; CHECK:   [[S_MOV_B32_:%[0-9]+]]:sreg_32 = S_MOV_B32 0
+  ; CHECK:   S_BRANCH %bb.3
+  ; CHECK: bb.2:
+  ; CHECK:   successors: %bb.3(0x80000000)
+  ; CHECK:   [[DEF:%[0-9]+]]:sreg_32 = IMPLICIT_DEF
+  ; CHECK:   S_SLEEP 9
+  ; CHECK: bb.3:
+  ; CHECK:   successors: %bb.3(0x80000000)
+  ; CHECK:   [[PHI:%[0-9]+]]:sreg_32 = PHI [[DEF]], %bb.2, %1, %bb.3, [[S_MOV_B32_]], %bb.0
+  ; CHECK:   S_NOP 0, implicit [[PHI]]
+  ; CHECK:   S_SLEEP 1
+  ; CHECK:   [[S_MOV_B32_1:%[0-9]+]]:sreg_32 = S_MOV_B32 0
+  ; CHECK:   S_BRANCH %bb.3
+  bb.1:
+
+  bb.2:
+    %5:sreg_32 = S_MOV_B32 0
+    S_BRANCH %bb.4
+
+  bb.3:
+    S_SLEEP 9
+
+  bb.4:
+    S_NOP 0, implicit %5
+    S_SLEEP 1
+    S_BRANCH %bb.2
+
+...