Revert "Extract demangler out to separate source set"

This reverts commit 2f7fea1f191802c6bf38e881220e0acfdbfd289a.

Reason for revert: breaks autorollers

Original change's description:
> Extract demangler out to separate source set
>
> And add this as a dep to libtint_core_src and tint_ast_clone_fuzzer.
>
> Should fix chromium autoroller
>
> Change-Id: Ic5f43bae85e010839a1940c1ae2d570a9613d269
> Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/37708
> Commit-Queue: dan sinclair <dsinclair@chromium.org>
> Reviewed-by: Ryan Harrison <rharrison@chromium.org>
> Reviewed-by: dan sinclair <dsinclair@chromium.org>

TBR=rharrison@chromium.org,dsinclair@chromium.org,bclayton@google.com

Change-Id: If872d1655e13dd5d67f898a3d9a43c76b2866973
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/37845
Reviewed-by: Ben Clayton <bclayton@google.com>
Reviewed-by: dan sinclair <dsinclair@chromium.org>
Commit-Queue: Ben Clayton <bclayton@google.com>
diff --git a/BUILD.gn b/BUILD.gn
index a7d62a5..d51ecb4 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -222,21 +222,6 @@
 # use the build flags to control what is included, instead of trying to specify
 # the subsets that they want.
 
-source_set("tint_core_demangler") {
-  sources = [
-    "src/demangler.cc",
-    "src/demangler.h",
-  ]
-
-  configs += [ ":tint_common_config" ]
-  public_configs = [ ":tint_public_config" ]
-
-  if (build_with_chromium) {
-    configs -= [ "//build/config/compiler:chromium_code" ]
-    configs += [ "//build/config/compiler:no_chromium_code" ]
-  }
-}
-
 source_set("libtint_core_src") {
   sources = [
     "src/ast/access_control.cc",
@@ -412,6 +397,8 @@
     "src/ast/workgroup_decoration.h",
     "src/castable.cc",
     "src/castable.h",
+    "src/demangler.cc",
+    "src/demangler.h",
     "src/diagnostic/diagnostic.cc",
     "src/diagnostic/diagnostic.h",
     "src/diagnostic/formatter.cc",
@@ -475,8 +462,6 @@
     sources += [ "src/diagnostic/printer_other.cc" ]
   }
 
-  deps = [ ":tint_core_demangler" ]
-
   public_deps = [
     ":tint_core_enums_unified1",
     ":tint_core_tables_unified1",
@@ -1440,10 +1425,7 @@
   if (tint_build_wgsl_reader && tint_build_wgsl_writer) {
     fuzzer_test("tint_ast_clone_fuzzer") {
       sources = [ "fuzzers/tint_ast_clone_fuzzer.cc" ]
-      deps = [
-        ":tint_fuzzer_common",
-        ":tint_core_demangler",
-      ]
+      deps = [ ":tint_fuzzer_common" ]
     }
   }
 }