update gcc toolchain (#75)

Change-Id: I9403ad449178aa0eb92c1169d0ee381c319e7d5a

WORKSPACE.bazel

@@ -35,26 +35,27 @@ host_system_libraries(
 
 load("@host_system_libraries//:defs.bzl", "HOST_SYSTEM_LIBRARIES")
 
-# Note: not correcton MacOS.
+# Note: not correct on MacOS.
 LLVM_COLOR_FLAGS = ["-fdiagnostics-color=always" if "libinfo.so.5" in HOST_SYSTEM_LIBRARIES else ""]
 
-BAZEL_BOOTLIN_COMMIT = "eae108c14445074ab5c8ae7f5338eebf1873ae69"
+BAZEL_BOOTLIN_COMMIT = "10638e74e907689abf9b7dc81aad05c588879079"
 
 http_archive(
     name = "bazel_bootlin",
-    sha256 = "ea76bcd8fc27da13bc79acc4844baadc563e07888a128265ca74d07cd58c1f34",
+    sha256 = "47bbb94a6277ff1ab579b23509ed6c076445b9d99195b4df0aba069298ae3f1c",
     strip_prefix = "bazel_bootlin-%s" % BAZEL_BOOTLIN_COMMIT,
     url = "https://github.com/oliverlee/bazel_bootlin/archive/%s.tar.gz" % BAZEL_BOOTLIN_COMMIT,
 )
 
 load("@bazel_bootlin//:defs.bzl", "bootlin_toolchain")
 
-# for mapping from buildroot version to gcc version
-# see https://toolchains.bootlin.com/releases_x86-64.html
 bootlin_toolchain(
     name = "gcc_toolchain",
-    architecture = "x86-64",
-    buildroot_version = "bleeding-edge-2022.08-1",
+    # x86-64-v3 should cover CPUs released after ~2015.
+    # see https://www.phoronix.com/news/GCC-11-x86-64-Feature-Levels.
+    architecture = "x86-64-v3",
+    # see https://toolchains.bootlin.com/releases_x86-64-v3.html
+    buildroot_version = "bleeding-edge-2023.08-1",
     extra_cxx_flags = [
         "-fdiagnostics-color=always",
         "-std=c++23",