gowin: support for locales other than en_US and C

Specifically, those locales where the fractional part separator in
floating point numbers is not a dot.

Signed-off-by: YRabbit <rabbit@yrabbit.cyou>

gowin/main.cc

@@ -21,6 +21,7 @@
 #ifdef MAIN_EXECUTABLE
 
 #include <fstream>
+#include <locale>
 #include <regex>
 #include "command.h"
 #include "design_utils.h"
@@ -90,6 +91,11 @@ void GowinCommandHandler::customAfterLoad(Context *ctx)
 
 int main(int argc, char *argv[])
 {
+    // set the locale here because when you create a context you create several
+    // floating point strings whose representation depends on the locale. If
+    // you don't do this, the strings will be in the C locale and later when Qt
+    // starts it won't be able to read them back as numbers.
+    std::locale::global(std::locale(""));
     GowinCommandHandler handler(argc, argv);
     return handler.exec();
 }