[bazel] Port 6497283

Author: d0k

utils/bazel/llvm-project-overlay/llvm/BUILD.bazel

@@ -2362,6 +2362,7 @@ gentbl(
         ("-gen-global-isel-combiner -combiners=RISCVO0PreLegalizerCombiner", "lib/Target/RISCV/RISCVGenO0PreLegalizeGICombiner.inc"),
         ("-gen-global-isel-combiner -combiners=RISCVPostLegalizerCombiner", "lib/Target/RISCV/RISCVGenPostLegalizeGICombiner.inc"),
         ("-gen-global-isel-combiner -combiners=RISCVPreLegalizerCombiner", "lib/Target/RISCV/RISCVGenPreLegalizeGICombiner.inc"),
+        ("-gen-global-isel-combiner -combiners=RISCVPostLegalizerLowering", "lib/Target/RISCV/RISCVGenPostLegalizeGILowering.inc"),
     ],
     tblgen = ":llvm-tblgen",
     td_file = "lib/Target/RISCV/RISCVGISel.td",