Update CMAKE_CXX_STANDARD in generate_build_files.py

Bug: 42290600
Change-Id: I448cc8c2e4cd54b5021b0ee04191852ef466d169
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/75087
Auto-Submit: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>

util/generate_build_files.py

diff --git a/util/generate_build_files.py b/util/generate_build_files.py
index c97376d..30c5833 100644
--- a/util/generate_build_files.py
+++ b/util/generate_build_files.py
@@ -404,7 +404,7 @@
 
 project(BoringSSL LANGUAGES C CXX)
 
-set(CMAKE_CXX_STANDARD 14)
+set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_C_STANDARD 11)
 set(CMAKE_C_STANDARD_REQUIRED ON)