Added flag for disabling HLSL intrinsics

Author: Przemog1

include/dxc/Support/HLSLOptions.td

@@ -601,3 +601,6 @@ def rw_decl_global_cb : Flag<["-", "/"], "decl-global-cb">, Group<hlslrewrite_Gr
   HelpText<"Collect all global constants outside cbuffer declarations into cbuffer GlobalCB { ... }. Still experimental, not all dependency scenarios handled.">;
 // Also removed: compress, decompress, /Gch (child effect), /Gpp (partial precision)
 // /Op - no support for preshaders.
+
+def devsh_disable_hlsl_intrinsics : Flag<["-"], "devsh-disable-hlsl-intrinsics">, Group<spirv_Group>, Flags<[CoreOption, DriverOption]>,
+  HelpText<"Disable HLSL intrinsics">;

include/dxc/Support/SPIRVOptions.h

@@ -38,6 +38,7 @@ enum class SpirvLayoutRule {
 };
 
 struct SpirvCodeGenOptions {
+  bool devshDisableHLSLIntrinsics;
   /// Disable legalization and optimization and emit raw SPIR-V
   bool codeGenHighLevel;
   bool debugInfoFile;

lib/DxcSupport/HLSLOptions.cpp

@@ -1074,6 +1074,8 @@ int ReadDxcOpts(const OptTable *optionTable, unsigned flagsToInclude,
 
   // SPIRV Change Starts
 #ifdef ENABLE_SPIRV_CODEGEN
+  opts.SpirvOptions.devshDisableHLSLIntrinsics =
+      Args.hasFlag(OPT_devsh_disable_hlsl_intrinsics, OPT_INVALID, false);
   opts.GenSPIRV = Args.hasFlag(OPT_spirv, OPT_INVALID, false);
   opts.SpirvOptions.invertY =
       Args.hasFlag(OPT_fvk_invert_y, OPT_INVALID, false);