[RISCV] Use reportFatalUsageError in a few places (#166218)

Makes it consistent with feedback given in the equivalent GISel code.
#165876

Author: topperc

llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp

@@ -371,8 +371,8 @@ void RISCVDAGToDAGISel::selectVLXSEG(SDNode *Node, unsigned NF, bool IsMasked,
   RISCVVType::VLMUL IndexLMUL = RISCVTargetLowering::getLMUL(IndexVT);
   unsigned IndexLog2EEW = Log2_32(IndexVT.getScalarSizeInBits());
   if (IndexLog2EEW == 6 && !Subtarget->is64Bit()) {
-    report_fatal_error("The V extension does not support EEW=64 for index "
-                       "values when XLEN=32");
+    reportFatalUsageError("The V extension does not support EEW=64 for index "
+                          "values when XLEN=32");
   }
   const RISCV::VLXSEGPseudo *P = RISCV::getVLXSEGPseudo(
       NF, IsMasked, IsOrdered, IndexLog2EEW, static_cast<unsigned>(LMUL),
@@ -444,8 +444,8 @@ void RISCVDAGToDAGISel::selectVSXSEG(SDNode *Node, unsigned NF, bool IsMasked,
   RISCVVType::VLMUL IndexLMUL = RISCVTargetLowering::getLMUL(IndexVT);
   unsigned IndexLog2EEW = Log2_32(IndexVT.getScalarSizeInBits());
   if (IndexLog2EEW == 6 && !Subtarget->is64Bit()) {
-    report_fatal_error("The V extension does not support EEW=64 for index "
-                       "values when XLEN=32");
+    reportFatalUsageError("The V extension does not support EEW=64 for index "
+                          "values when XLEN=32");
   }
   const RISCV::VSXSEGPseudo *P = RISCV::getVSXSEGPseudo(
       NF, IsMasked, IsOrdered, IndexLog2EEW, static_cast<unsigned>(LMUL),
@@ -2223,8 +2223,8 @@ void RISCVDAGToDAGISel::Select(SDNode *Node) {
       RISCVVType::VLMUL IndexLMUL = RISCVTargetLowering::getLMUL(IndexVT);
       unsigned IndexLog2EEW = Log2_32(IndexVT.getScalarSizeInBits());
       if (IndexLog2EEW == 6 && !Subtarget->is64Bit()) {
-        report_fatal_error("The V extension does not support EEW=64 for index "
-                           "values when XLEN=32");
+        reportFatalUsageError("The V extension does not support EEW=64 for "
+                              "index values when XLEN=32");
       }
       const RISCV::VLX_VSXPseudo *P = RISCV::getVLXPseudo(
           IsMasked, IsOrdered, IndexLog2EEW, static_cast<unsigned>(LMUL),
@@ -2457,8 +2457,8 @@ void RISCVDAGToDAGISel::Select(SDNode *Node) {
       RISCVVType::VLMUL IndexLMUL = RISCVTargetLowering::getLMUL(IndexVT);
       unsigned IndexLog2EEW = Log2_32(IndexVT.getScalarSizeInBits());
       if (IndexLog2EEW == 6 && !Subtarget->is64Bit()) {
-        report_fatal_error("The V extension does not support EEW=64 for index "
-                           "values when XLEN=32");
+        reportFatalUsageError("The V extension does not support EEW=64 for "
+                              "index values when XLEN=32");
       }
       const RISCV::VLX_VSXPseudo *P = RISCV::getVSXPseudo(
           IsMasked, IsOrdered, IndexLog2EEW,