Update clang for standalone builds

Catch up with chromium

Change-Id: I485a362d9142dbfb7a4a1a78a2f842258ae40e22
diff --git a/buildtools/BUILD.gn b/buildtools/BUILD.gn
index 6a44fbe..1d6e039 100644
--- a/buildtools/BUILD.gn
+++ b/buildtools/BUILD.gn
@@ -1421,7 +1421,10 @@
   ]
   cflags = [ "-DFAKE_LOG_DEVICE=1" ]
   if (!is_win) {
-    cflags += [ "-Wno-deprecated-declarations" ]
+    cflags += [
+      "-Wno-deprecated-declarations",
+      "-Wno-vla-cxx-extension",
+    ]
   }
   public_configs = [ ":libunwindstack_config" ]
 }
diff --git a/gn/standalone/BUILD.gn b/gn/standalone/BUILD.gn
index c397d5c..43c81d0 100644
--- a/gn/standalone/BUILD.gn
+++ b/gn/standalone/BUILD.gn
@@ -89,6 +89,10 @@
       "-Wno-unknown-sanitizers",
       "-Wno-unknown-warning-option",
       "-Wno-unsafe-buffer-usage",
+
+      # TODO(primiano): -Wswitch-default could be useful but will require a mass
+      # codebase cleanup.
+      "-Wno-switch-default",
     ]
   } else if (!is_clang && !is_win) {
     # Use return std::move(...) for compatibility with old GCC compilers.
diff --git a/tools/install-build-deps b/tools/install-build-deps
index 802ae9e..d1efa23 100755
--- a/tools/install-build-deps
+++ b/tools/install-build-deps
@@ -165,13 +165,13 @@
     # tools/clang/scripts/update.py.
     Dependency(
         'buildtools/linux64/clang.tgz',
-        'https://commondatastorage.googleapis.com/chromium-browser-clang/Linux_x64/clang-llvmorg-16-init-8697-g60809cd2-1.tgz',
-        '5ae35f85e0d32136795c6b223bf64263d46678dd4a24fea4e9039e58a32670de',
+        'https://commondatastorage.googleapis.com/chromium-browser-clang/Linux_x64/clang-llvmorg-18-init-17730-gf670112a-5.tgz',
+        'ce6201b728ea485d4b116aa3b5e8ae3b34ee2775f25924c5714fdbe42fb2b787',
         'linux', 'x64'),
     Dependency(
         'buildtools/win/clang.tgz',
-        'https://commondatastorage.googleapis.com/chromium-browser-clang/Win/clang-llvmorg-16-init-8697-g60809cd2-1.tgz',
-        '086faec822acba5b9c0308c6a8be34424031027d757efa2b81805aed18ffc521',
+        'https://commondatastorage.googleapis.com/chromium-browser-clang/Win/clang-llvmorg-18-init-17730-gf670112a-5.tgz',
+        '972011cc8a5bc5d5fbe08773089058a264ee0e19af019df28f0972ee9bd0493f',
         'windows', 'x64'),
 ]