build: add dependency on sil-llvm-gen for tests

sil-llvm-gen/alloc.sil uses this tool during tests, but was missing a
dependency.  `ninja -t clean; ninja check-swift` would fail as a result.

Author: compnerd

test/CMakeLists.txt

@@ -41,7 +41,7 @@ function(get_test_dependencies SDK result_var_name)
 
   set(deps_binaries
       swift swift-ide-test sil-opt swift-llvm-opt swift-demangle
-      sil-func-extractor sil-nm sil-passpipeline-dumper
+      sil-func-extractor sil-llvm-gen sil-nm sil-passpipeline-dumper
       lldb-moduleimport-test swift-reflection-dump swift-remoteast-test
       swift-api-digester)
   if(NOT SWIFT_BUILT_STANDALONE)