[bazel] Port 8e87dc1 (RISCVPostLegalizerCombiner)

Author: MaskRay

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

@@ -2191,6 +2191,7 @@ gentbl(
     tbl_outs = [
       ("-gen-global-isel", "lib/Target/RISCV/RISCVGenGlobalISel.inc"),
       ("-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"),
     ],
     tblgen = ":llvm-tblgen",