Refactor with hasMixedPendingEvents. NFC.

This is just stylistic. It allows using the identical condition in the
SMEM and VMEM cases and potentially guards against more X_CNT event
types being added in future.

Author: jayfoad

llvm/lib/Target/AMDGPU/SIInsertWaitcnts.cpp

@@ -1296,7 +1296,7 @@ void WaitcntBrackets::applyXcnt(const AMDGPU::Waitcnt &Wait) {
   // SMEM can return out of order, so only omit XCNT wait if we are waiting till
   // zero.
   if (Wait.KmCnt == 0 && hasPendingEvent(SMEM_GROUP)) {
-    if (hasPendingEvent(VMEM_GROUP))
+    if (hasMixedPendingEvents(X_CNT))
       PendingEvents &= ~(1 << SMEM_GROUP);
     else
       applyWaitcnt(X_CNT, 0);
@@ -1308,7 +1308,7 @@ void WaitcntBrackets::applyXcnt(const AMDGPU::Waitcnt &Wait) {
   // decremented to the same number as LOADCnt.
   if (Wait.LoadCnt != ~0u && hasPendingEvent(VMEM_GROUP) &&
       !hasPendingEvent(STORE_CNT)) {
-    if (hasPendingEvent(SMEM_GROUP))
+    if (hasMixedPendingEvents(X_CNT))
       PendingEvents &= ~(1 << VMEM_GROUP);
     else
       applyWaitcnt(X_CNT, std::min(Wait.XCnt, Wait.LoadCnt));