BEGIN_PUBLIC
Remove /Z7 from default Windows fastbuild compile flags

Previously, fastbuild was the same as dbg, which makes no sense.  Both used
/Od /Z7 (disable optimization, full debug info).

The /Z7 flag generates debug information in object files, which greatly increases
object file output size and somewhat increases compilation time.

In https://github.com/google-research/openfst we were seeing 1.8GB of compressed
output.  GitHub only allows 10GB of cache.  Removing /Z7 reduces 1.8GB to 300MB.

Users who want debug symbols should use -c dbg.
END_PUBLIC

PiperOrigin-RevId: 914096297
Change-Id: Ib5fd637874394163db63298d673d5a2b4ead678c

cc/private/toolchain/windows_cc_toolchain_config.bzl

diff --git a/cc/private/toolchain/windows_cc_toolchain_config.bzl b/cc/private/toolchain/windows_cc_toolchain_config.bzl
index 295f481..1ba5302 100644
--- a/cc/private/toolchain/windows_cc_toolchain_config.bzl
+++ b/cc/private/toolchain/windows_cc_toolchain_config.bzl
@@ -547,7 +547,7 @@
             flag_sets = [
                 flag_set(
                     actions = [ACTION_NAMES.c_compile, ACTION_NAMES.cpp_compile],
-                    flag_groups = [flag_group(flags = ["/Od", "/Z7"])],
+                    flag_groups = [flag_group(flags = ["/Od"])],
                 ),
                 flag_set(
                     actions = all_link_actions,