Address remaining Copilot PR comments

Author: napetrov

dev/bazel/release.bzl

@@ -18,10 +18,12 @@ load("@onedal//dev/bazel:utils.bzl", "utils", "paths")
 load("@onedal//dev/bazel:cc.bzl", "ModuleInfo")
 load("@rules_cc//cc/common:cc_info.bzl", "CcInfo")
 
-# Transition: force --cpu=all when building release libs,
-# unless --cpu is explicitly overridden (e.g. --cpu=avx2 in CI).
-# This ensures bazel build //:release compiles all ISA variants
-# (sse2, sse42, avx2, avx512) by default without any extra flags.
+# Transition: force --cpu=all when building release libs and headers.
+# This ensures `bazel build //:release` compiles all ISA variants
+# (sse2, sse42, avx2, avx512) by default without extra flags.
+# Note: Bazel does not distinguish between an unset `--cpu` and an
+# explicit `--cpu=auto`. In both cases, this transition forces `all`.
+# Explicit non-auto overrides (e.g. `--cpu=avx2`) are respected.
 def _release_cpu_all_impl(settings, attr):
     current = settings["@config//:cpu"]
     # Respect explicit --cpu flag; only force "all" for the default "auto".

dev/bazel/tests/isa_coverage_test.sh

@@ -42,7 +42,7 @@ check_isa() {
     local cpu_type="$1"   # e.g. CpuTypeE2
     local isa_name="$2"   # e.g. sse42
     local count
-    count=$(nm -D "${LIB}" | grep -c "${cpu_type}" || true)
+    count=$(nm -D --defined-only "${LIB}" | grep -c "${cpu_type}" || true)
     if [[ "${count}" -gt 0 ]]; then
         echo "  OK  ${isa_name} (${cpu_type}): ${count} dispatch symbols"
         PASS=$((PASS + 1))