Revert "[gn build] Port 6497283"

This reverts commit 98cf656.
6497283 was reverted in 9c5ad62

Author: nico

llvm/utils/gn/secondary/llvm/lib/Target/RISCV/BUILD.gn

@@ -68,15 +68,6 @@ tablegen("RISCVGenPostLegalizeGICombiner") {
   td_file = "RISCVGISel.td"
 }
 
-tablegen("RISCVGenPostLegalizeGILowering") {
-  visibility = [ ":LLVMRISCVCodeGen" ]
-  args = [
-    "-gen-global-isel-combiner",
-    "-combiners=RISCVPostLegalizerLowering",
-  ]
-  td_file = "RISCVGISel.td"
-}
-
 tablegen("RISCVGenRegisterBank") {
   visibility = [ ":LLVMRISCVCodeGen" ]
   args = [ "-gen-register-bank" ]
@@ -92,7 +83,6 @@ static_library("LLVMRISCVCodeGen") {
     ":RISCVGenMacroFusion",
     ":RISCVGenO0PreLegalizeGICombiner",
     ":RISCVGenPostLegalizeGICombiner",
-    ":RISCVGenPostLegalizeGILowering",
     ":RISCVGenPreLegalizeGICombiner",
     ":RISCVGenRegisterBank",
 
@@ -119,7 +109,6 @@ static_library("LLVMRISCVCodeGen") {
     "GISel/RISCVLegalizerInfo.cpp",
     "GISel/RISCVO0PreLegalizerCombiner.cpp",
     "GISel/RISCVPostLegalizerCombiner.cpp",
-    "GISel/RISCVPostLegalizerLowering.cpp",
     "GISel/RISCVPreLegalizerCombiner.cpp",
     "GISel/RISCVRegisterBankInfo.cpp",
     "RISCVAsmPrinter.cpp",