build: Add and build piper submodule.

CW-Bug-Id: #18723
CW-Bug-Id: #20918
CW-Bug-Id: #21959
CW-Bug-Id: #22520
CW-Bug-Id: #22894

.gitmodules

@@ -55,3 +55,7 @@
 [submodule "glslang"]
 	path = glslang
 	url = https://github.com/KhronosGroup/glslang
+[submodule "piper"]
+	path = piper
+	url = https://github.com/shaunren/piper.git
+	branch = library

Makefile.in

@@ -385,6 +385,19 @@ $(OBJ)/.steamexe-post-build64:
 	cp $(SRC)/steam_helper/64/libsteam_api.so $(DST_LIBDIR64)/
 	touch $@
 
+##
+## piper
+##
+
+$(eval $(call rules-source,piper,$(SRCDIR)/piper))
+$(eval $(call rules-cmake,piper,64))
+
+$(OBJ)/.piper-post-build64:
+	mkdir -p $(PIPER_DST64)/lib64
+	mkdir -p $(DST_DIR)/share
+	mv $(PIPER_DST64)/*.so* $(PIPER_DST64)/lib64/
+	cp -a $(PIPER_DST64)/{espeak-ng-data,libtashkeel_model.ort} $(DST_DIR)/share/
+	touch $@
 
 ##
 ## wine
@@ -423,6 +436,7 @@ WINE_CONFIGURE_ARGS64 = --enable-win64 \
   VKD3D_PE_LIBS="-L$(VKD3D_DST64)/bin -l:libvkd3d-1.dll -l:libvkd3d-shader-1.dll"
 
 WINE_DEPENDS = gst_orc gstreamer gst_base vkd3d ffmpeg
+WINE_DEPENDS64 = piper
 
 $(eval $(call rules-source,wine,$(SRCDIR)/wine))
 $(eval $(call rules-autoconf,wine,32))

piper

@@ -0,0 +1 @@
+Subproject commit 9d06b74959570772e8bcbe7a3f696664d2421167

proton

@@ -1403,6 +1403,8 @@ class Session:
         self.env["MEDIACONV_BLANK_VIDEO_FILE"] = g_proton.media_dir + "blank.mkv"
         self.env["MEDIACONV_BLANK_AUDIO_FILE"] = g_proton.media_dir + "blank.ptna"
 
+        self.env["ESPEAK_DATA_PATH"] = g_proton.dist_dir + "share"
+
         prepend_to_env_str(self.env, "PATH", g_proton.bin_dir, ":")
 
     def check_environment(self, env_name, config_name):