MSL: Return fragment function value even when last SPIR-V Op is discard (OpKill).

Add test shader for new functionality.
Add legacy test reference shader for unrelated buffer-bitcast
test, that doesn't seem to have been added previously.

1 files changed, 2 insertions, 1 deletions

diff --git a/spirv_msl.cpp b/spirv_msl.cpp
index d20f1643..06e27e59 100644
--- a/spirv_msl.cpp
+++ b/spirv_msl.cpp
@@ -3467,6 +3467,7 @@ uint32_t CompilerMSL::add_interface_block(StorageClass storage, bool patch)
 		// Add the output interface struct as a local variable to the entry function.
 		// If the entry point should return the output struct, set the entry function
 		// to return the output interface struct, otherwise to return nothing.
+		// Watch out for the rare case where the terminator of the last entry point block is a Kill, instead of a Return.
 		// Indicate the output var requires early initialization.
 		bool ep_should_return_output = !get_is_rasterization_disabled();
 		uint32_t rtn_id = ep_should_return_output ? ib_var_id : 0;
@@ -3476,7 +3477,7 @@ uint32_t CompilerMSL::add_interface_block(StorageClass storage, bool patch)
 			for (auto &blk_id : entry_func.blocks)
 			{
 				auto &blk = get<SPIRBlock>(blk_id);
-				if (blk.terminator == SPIRBlock::Return)
+				if (blk.terminator == SPIRBlock::Return || (blk.terminator == SPIRBlock::Kill && blk_id == entry_func.blocks.back()))
 					blk.return_value = rtn_id;
 			}
 			vars_needing_early_declaration.push_back(ib_var_id);