Update warnings for newer clang.

There are a few warnings appearing with newer Clang. This CL disables
them.

Change-Id: I6d665ba7e9df8e1078e062b63296ad9bfaf16cd6
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/116550
Commit-Queue: Dan Sinclair <dsinclair@chromium.org>
Reviewed-by: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>

CMakeLists.txt

@@ -318,6 +318,8 @@ function(common_compile_options TARGET)
     target_compile_options(${TARGET} PRIVATE
       -fno-exceptions
       -fno-rtti
+
+      -Wno-deprecated-builtins
     )
 
     if (${DAWN_ENABLE_MSAN})
@@ -540,6 +542,7 @@ function(tint_default_compile_options TARGET)
     -Wno-return-std-move-in-c++11
     -Wno-unknown-warning-option
     -Wno-undefined-var-template
+    -Wno-unsafe-buffer-usage
     -Wno-used-but-marked-unused
     -Weverything
   )

third_party/CMakeLists.txt

@@ -64,6 +64,15 @@ endif()
 
 if (NOT TARGET libabsl)
     message(STATUS "Dawn: using Abseil at ${DAWN_ABSEIL_DIR}")
+    if (("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang") OR
+        ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "AppleClang"))
+        add_compile_options(
+            -Wno-array-parameter
+            -Wno-deprecated-builtins
+            -Wno-unknown-warning-option
+        )
+    endif()
+
     add_subdirectory(${DAWN_ABSEIL_DIR} "${CMAKE_CURRENT_BINARY_DIR}/abseil")
 endif()