[flang] Restore Optional::value() (NFC)

This patch restores several calls to Optional::value() in preference
to Optional::operator*.

The Flang C++ Style Guide tells us to use x.value() where no presence
test is obviously protecting a *x reference to the contents.

Differential Revision: https://reviews.llvm.org/D128590

Author: kazutakahirata

flang/lib/Lower/ConvertExpr.cpp

@@ -3950,8 +3950,9 @@ class ArrayExprLowering {
       mlir::Value oldInnerArg = modifyOp.getSequence();
       std::size_t offset = explicitSpace->argPosition(oldInnerArg);
       explicitSpace->setInnerArg(offset, fir::getBase(lexv));
-      fir::ExtendedValue exv = arrayModifyToExv(
-          builder, loc, *explicitSpace->getLhsLoad(0), modifyOp.getResult(0));
+      fir::ExtendedValue exv =
+          arrayModifyToExv(builder, loc, explicitSpace->getLhsLoad(0).value(),
+                           modifyOp.getResult(0));
       genScalarUserDefinedAssignmentCall(builder, loc, userAssignment, exv,
                                          elementalExv);
     } else {
@@ -4101,7 +4102,7 @@ class ArrayExprLowering {
                                       mlir::Value origVal) {
     mlir::Value val = builder.createConvert(loc, eleTy, origVal);
     if (isBoundsSpec()) {
-      auto lbs = *lbounds;
+      auto lbs = lbounds.value();
       if (lbs.size() > 0) {
         // Rebox the value with user-specified shift.
         auto shiftTy = fir::ShiftType::get(eleTy.getContext(), lbs.size());
@@ -6368,7 +6369,7 @@ class ArrayExprLowering {
         charLen = builder.createTemporary(loc, builder.getI64Type());
         mlir::Value castLen =
             builder.createConvert(loc, builder.getI64Type(), fir::getLen(exv));
-        builder.create<fir::StoreOp>(loc, castLen, *charLen);
+        builder.create<fir::StoreOp>(loc, castLen, charLen.value());
       }
     }
     stmtCtx.finalize(/*popScope=*/true);
@@ -6382,7 +6383,7 @@ class ArrayExprLowering {
 
     // Convert to extended value.
     if (fir::isa_char(seqTy.getEleTy())) {
-      auto len = builder.create<fir::LoadOp>(loc, *charLen);
+      auto len = builder.create<fir::LoadOp>(loc, charLen.value());
       return {fir::CharArrayBoxValue{mem, len, extents}, /*needCopy=*/false};
     }
     return {fir::ArrayBoxValue{mem, extents}, /*needCopy=*/false};
@@ -6450,7 +6451,7 @@ class ArrayExprLowering {
         charLen = builder.createTemporary(loc, builder.getI64Type());
         mlir::Value castLen =
             builder.createConvert(loc, builder.getI64Type(), fir::getLen(exv));
-        builder.create<fir::StoreOp>(loc, castLen, *charLen);
+        builder.create<fir::StoreOp>(loc, castLen, charLen.value());
       }
     }
     mem = builder.createConvert(loc, fir::HeapType::get(resTy), mem);

flang/lib/Optimizer/CodeGen/CodeGen.cpp

@@ -2818,7 +2818,7 @@ struct SelectCaseOpConversion : public FIROpConversion<fir::SelectCaseOp> {
           caseOp.getSuccessorOperands(adaptor.getOperands(), t);
       llvm::Optional<mlir::ValueRange> cmpOps =
           *caseOp.getCompareOperands(adaptor.getOperands(), t);
-      mlir::Value caseArg = *(cmpOps->begin());
+      mlir::Value caseArg = *(cmpOps.value().begin());
       mlir::Attribute attr = cases[t];
       if (attr.isa<fir::PointIntervalAttr>()) {
         auto cmp = rewriter.create<mlir::LLVM::ICmpOp>(
@@ -2847,7 +2847,7 @@ struct SelectCaseOpConversion : public FIROpConversion<fir::SelectCaseOp> {
         rewriter.setInsertionPointToEnd(thisBlock);
         rewriter.create<mlir::LLVM::CondBrOp>(loc, cmp, newBlock1, newBlock2);
         rewriter.setInsertionPointToEnd(newBlock1);
-        mlir::Value caseArg0 = *(cmpOps->begin() + 1);
+        mlir::Value caseArg0 = *(cmpOps.value().begin() + 1);
         auto cmp0 = rewriter.create<mlir::LLVM::ICmpOp>(
             loc, mlir::LLVM::ICmpPredicate::sle, selector, caseArg0);
         genCondBrOp(loc, cmp0, dest, destOps, rewriter, newBlock2);