[vulkan] glslang - Update Vulkan ecosystem to v1.2.174.

Merge commit 'a7f846a86cb2c82445b6310c449408bb66959a01' into v1.2.174-jr

Change-Id: I0e390b25ce4334a2a253d2fdb14e82327476efdb
diff --git a/BUILD.gn b/BUILD.gn
index 973ca98..dd31806 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -83,6 +83,8 @@
 
 config("glslang_hlsl") {
   defines = [ "ENABLE_HLSL=1" ]
+
+  cflags = [ "-Wno-conversion" ]
 }
 
 template("glslang_sources_common") {
@@ -231,6 +233,11 @@
         "-Wno-ignored-qualifiers",
         "-Wno-implicit-fallthrough",
         "-Wno-inconsistent-missing-override",
+
+        # TODO(rosasco): Fuchsia-only flags
+        "-Wno-unused-variable",
+        "-Wno-unknown-warning-option",
+
         "-Wno-missing-field-initializers",
         "-Wno-newline-eof",
         "-Wno-sign-compare",
@@ -239,6 +246,7 @@
         "-Wno-unused-variable",
       ]
     }
+
     if (is_win && !is_clang) {
       cflags = [
         "/wd4018",  # signed/unsigned mismatch