Force -Wno-shadow to avoid variable shadowing warnings.

Long term, ideally, these would be fixed and this flag can be removed.
For now, this is an expedient way to allow enabling -Wshadow in
Chromium.

Bug: chromium:794619
Change-Id: I95f806dd3ec6b162e84596b3a632901af41f41b0
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/57228
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Tested-by: Peter Kasting <pkasting@google.com>
Commit-Queue: Peter Kasting <pkasting@google.com>

BUILD.gn

diff --git a/BUILD.gn b/BUILD.gn
index 413c977..37f7de1 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -15,7 +15,7 @@
 import("src/Reactor/reactor.gni")
 
 config("swiftshader_config") {
-  cflags = []
+  cflags = [ "-Wno-shadow" ]
   defines = []
   asmflags = []
 
@@ -81,6 +81,7 @@
   }
   include_dirs = [ "src/" ]
   deps = [ "src/OpenGL/libGLESv2:swiftshader_libGLESv2_static" ]
+  configs += [ ":swiftshader_config" ]
 }
 
 group("swiftshader") {

tests/ReactorUnitTests/BUILD.gn

diff --git a/tests/ReactorUnitTests/BUILD.gn b/tests/ReactorUnitTests/BUILD.gn
index 877c0a4..44a46d0 100644
--- a/tests/ReactorUnitTests/BUILD.gn
+++ b/tests/ReactorUnitTests/BUILD.gn
@@ -25,6 +25,8 @@
       "//third_party/swiftshader/src/Reactor:swiftshader_llvm_reactor",
     ]
 
+    configs += [ "//third_party/swiftshader:swiftshader_config" ]
+
     sources = [
       "//gpu/swiftshader_tests_main.cc",
       "ReactorUnitTests.cpp",
@@ -46,6 +48,8 @@
       "//third_party/swiftshader/src/Reactor:swiftshader_subzero_reactor",
     ]
 
+    configs += [ "//third_party/swiftshader:swiftshader_config" ]
+
     sources = [
       "//gpu/swiftshader_tests_main.cc",
       "ReactorUnitTests.cpp",