GCC: fix build error due to deprecated declarations warning

GCC 12 fails to build swiftshader from CMake with recent libstdc++
because of using deprecated declarations in the LLVM 10 copy inside
SwiftShader.

This change removes those warnings, as they were also removed in
Clang.

Bug: swiftshader:181
Change-Id: I1daf7812a8d696dcdbf98626bf39c125163cd828
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/71090
Commit-Queue: Shahbaz Youssefi <syoussefi@google.com>
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Tested-by: Shahbaz Youssefi <syoussefi@google.com>
Reviewed-by: Shahbaz Youssefi <syoussefi@google.com>
diff --git a/third_party/llvm-10.0/CMakeLists.txt b/third_party/llvm-10.0/CMakeLists.txt
index bef287b..9f55d48 100644
--- a/third_party/llvm-10.0/CMakeLists.txt
+++ b/third_party/llvm-10.0/CMakeLists.txt
@@ -1229,6 +1229,7 @@
     list(APPEND LLVM_COMPILE_OPTIONS
         "-Wno-noexcept-type"           # mangled name for ‘X’ will change in C++17 because the exception specification is part of a function type
         "-Wno-maybe-uninitialized"     # ‘X’ may be used uninitialized in this function
+        "-Wno-deprecated-declarations"
     )
     if(CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 8)
         list(APPEND LLVM_COMPILE_OPTIONS