added Windows host support

toolchain/private/BUILD.sdk.bazel

@@ -1,6 +1,7 @@
 load("@bazel-zig-cc//toolchain/private:cc_toolchains.bzl", "declare_cc_toolchains")
 
 declare_cc_toolchains(
+    os = {os},
     absolute_path = {absolute_path},
     zig_include_root = {zig_include_root},
 )

toolchain/private/cc_toolchains.bzl

@@ -1,4 +1,4 @@
-load(":defs.bzl", "DEFAULT_INCLUDE_DIRECTORIES", "ZIG_TOOL_PATH", "target_structs")
+load(":defs.bzl", "DEFAULT_INCLUDE_DIRECTORIES", "target_structs", "zig_tool_path")
 load("@bazel-zig-cc//toolchain:zig_toolchain.bzl", "zig_cc_toolchain_config")
 
 DEFAULT_TOOL_PATHS = {
@@ -11,7 +11,7 @@ DEFAULT_TOOL_PATHS = {
     "strip": "/usr/bin/false",
 }.items()
 
-def declare_cc_toolchains(absolute_path, zig_include_root):
+def declare_cc_toolchains(os, absolute_path, zig_include_root):
     for target_config in target_structs():
         gotarget = target_config.gotarget
         zigtarget = target_config.zigtarget
@@ -28,7 +28,7 @@ def declare_cc_toolchains(absolute_path, zig_include_root):
             if path[0] == "/":
                 absolute_tool_paths[name] = path
                 continue
-            tool_path = ZIG_TOOL_PATH.format(zig_tool = path)
+            tool_path = zig_tool_path(os).format(zig_tool = path)
             absolute_tool_paths[name] = "%s/%s" % (absolute_path, tool_path)
 
         linkopts = target_config.linkopts

toolchain/private/defs.bzl

@@ -4,7 +4,7 @@ DEFAULT_INCLUDE_DIRECTORIES = [
     "libcxxabi/include",
 ]
 
-ZIG_TOOL_PATH = "tools/{zig_tool}"
+_ZIG_TOOL_PATH = "tools/{zig_tool}"
 
 # Zig supports even older glibcs than defined below, but we have tested only
 # down to 2.17.
@@ -30,6 +30,12 @@ _GLIBCS = [
 
 LIBCS = ["musl"] + ["gnu.{}".format(glibc) for glibc in _GLIBCS]
 
+def zig_tool_path(os):
+    if os == "windows":
+        return _ZIG_TOOL_PATH + ".bat"
+    else:
+        return _ZIG_TOOL_PATH
+
 def target_structs():
     ret = []
     for zigcpu, gocpu in (("x86_64", "amd64"), ("aarch64", "arm64")):