[gn] port d86b68a more

See my comments on #88257.
(The AMDGPU target internal depencencies were among the messiest
among all targets even before that.)

Author: nico

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

@@ -60,6 +60,7 @@ tablegen("AMDGPUGenMCPseudoLowering") {
 tablegen("AMDGPUGenRegisterBank") {
   visibility = [
     ":LLVMAMDGPUCodeGen",
+    "MCTargetDesc",
     "Utils",
     "//llvm/unittests/MC/AMDGPU:AMDGPUMCTests",
     "//llvm/unittests/Target/AMDGPU:AMDGPUTests",

llvm/utils/gn/secondary/llvm/lib/Target/AMDGPU/MCTargetDesc/BUILD.gn

@@ -94,6 +94,10 @@ static_library("MCTargetDesc") {
     "//llvm/lib/Target/AMDGPU/TargetInfo",
     "//llvm/lib/Target/AMDGPU/Utils",
     "//llvm/lib/TargetParser",
+
+    # AMDGPUMCExpr.cpp includes GCNSubtarget.h which after 490e348e679
+    # includes the generated AMDGPUGenRegisterBank.inc file :/
+    "//llvm/lib/Target/AMDGPU/:AMDGPUGenRegisterBank",
   ]
   include_dirs = [ ".." ]
   sources = [