[mlir] Use llvm::append_range (NFC) (llvm#136257)

This patch replaces:

  llvm::copy(Src, std::back_inserter(Dst));

with:

  llvm::append_range(Dst, Src);

for breavity.

One side benefit is that llvm::append_range eventually calls
llvm::SmallVector::reserve if Dst is of llvm::SmallVector.

Author: kazutakahirata

mlir/lib/Dialect/EmitC/IR/EmitC.cpp

@@ -1337,7 +1337,7 @@ Block &emitc::SwitchOp::getCaseBlock(unsigned idx) {
 
 void SwitchOp::getSuccessorRegions(
     RegionBranchPoint point, SmallVectorImpl<RegionSuccessor> &successors) {
-  llvm::copy(getRegions(), std::back_inserter(successors));
+  llvm::append_range(successors, getRegions());
 }
 
 void SwitchOp::getEntrySuccessorRegions(
@@ -1348,7 +1348,7 @@ void SwitchOp::getEntrySuccessorRegions(
   // If a constant was not provided, all regions are possible successors.
   auto arg = dyn_cast_or_null<IntegerAttr>(adaptor.getArg());
   if (!arg) {
-    llvm::copy(getRegions(), std::back_inserter(successors));
+    llvm::append_range(successors, getRegions());
     return;
   }
 

mlir/lib/Dialect/SCF/IR/SCF.cpp

@@ -758,7 +758,7 @@ LoopNest mlir::scf::buildLoopNest(
 
   // Return the loops.
   ValueVector nestResults;
-  llvm::copy(loops.front().getResults(), std::back_inserter(nestResults));
+  llvm::append_range(nestResults, loops.front().getResults());
   return LoopNest{std::move(loops), std::move(nestResults)};
 }
 
@@ -4281,7 +4281,7 @@ void IndexSwitchOp::getSuccessorRegions(
     return;
   }
 
-  llvm::copy(getRegions(), std::back_inserter(successors));
+  llvm::append_range(successors, getRegions());
 }
 
 void IndexSwitchOp::getEntrySuccessorRegions(
@@ -4292,7 +4292,7 @@ void IndexSwitchOp::getEntrySuccessorRegions(
   // If a constant was not provided, all regions are possible successors.
   auto arg = dyn_cast_or_null<IntegerAttr>(adaptor.getArg());
   if (!arg) {
-    llvm::copy(getRegions(), std::back_inserter(successors));
+    llvm::append_range(successors, getRegions());
     return;
   }
 

mlir/lib/Dialect/Traits.cpp

@@ -70,9 +70,9 @@ bool OpTrait::util::getBroadcastedShape(ArrayRef<int64_t> shape1,
 
   resultShape.clear();
   if (shape1.size() > shape2.size()) {
-    std::copy(shape1.begin(), shape1.end(), std::back_inserter(resultShape));
+    llvm::append_range(resultShape, shape1);
   } else {
-    std::copy(shape2.begin(), shape2.end(), std::back_inserter(resultShape));
+    llvm::append_range(resultShape, shape2);
   }
 
   auto i1 = shape1.rbegin(), e1 = shape1.rend();