Symbian ^3 port

[I-asked]

Updating my old Symbian port to latest TIC-80 previews. Not sure if this is appropriate for inclusion in upstream, but I'll try nonetheless to perhaps gather some feedback. 🐱

This is WIP and will only work on Nokia E7. I need more S^3 phones to make keymaps for or start relying on the OS's IME which can be quite cumbersome both to set up and to use efficiently… Feedback very welcome. 😊

How to build

You'll need a Linux box preloaded with common devtools.

1. Setup your EPOCROOT using ERA
2. Clone this PR (recursively ofc), then cd…
3. git-apply the attached patch (see below) to vendor/zip
4. cmake -B _builddir/symbian -D CMAKE_TOOLCHAIN_FILE=build/symbian/cmake/toolchain-symbian-gcce.cmake
5. cmake --build _builddir/symbian -j -t tic80-sis
6. Install _builddir/symbian/tic80.sis on your Symbian ^3 device (Nokia E7)
7. 

What's left to be done

• We need people to test this on real devices and get them to report bugs! 😁
• Some languages are disabled, because they are unlikely to work without sending patches to upstream. 😞

vendor/zip patch

diff --git a/src/zip.c b/src/zip.c
index 4f17ec5..376e865 100644
--- a/src/zip.c
+++ b/src/zip.c
@@ -28,6 +28,9 @@
 #else
 
 #include <unistd.h> // needed for symlink() on BSD
+#ifdef __EPOC32__
+__declspec(dllimport)
+#endif
 int symlink(const char *target, const char *linkpath); // needed on Linux
 
 #define MKDIR(DIRNAME) mkdir(DIRNAME, 0755)