thirdparty: update all sokol and fontstash headers with their upstream versions (#16940)

vlib/sokol/sfons/sfons.c.v

@@ -2,13 +2,27 @@ module sfons
 
 import fontstash
 import sokol.f
+import sokol.memory
 
 // keep v from warning about unused imports
 const used_import = f.used_import + fontstash.used_import + 1
 
+// create a new Context/font atlas, for rendering glyphs, given its dimensions `width` and `height`
 [inline]
 pub fn create(width int, height int, flags int) &fontstash.Context {
-	return C.sfons_create(width, height, flags)
+	assert is_power_of_two(width)
+	assert is_power_of_two(height)
+	allocator := C.sfons_allocator_t{
+		alloc: memory.salloc
+		free: memory.sfree
+		user_data: voidptr(0x100005f0)
+	}
+	desc := C.sfons_desc_t{
+		width: width
+		height: height
+		allocator: allocator
+	}
+	return C.sfons_create(&desc)
 }
 
 [inline]
@@ -25,3 +39,7 @@ pub fn rgba(r u8, g u8, b u8, a u8) u32 {
 pub fn flush(ctx &fontstash.Context) {
 	C.sfons_flush(ctx)
 }
+
+fn is_power_of_two(x int) bool {
+	return x in [2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768]
+}

vlib/sokol/sfons/sfons_funcs.c.v

@@ -1,8 +1,26 @@
 module sfons
 
 import fontstash
+import sokol.memory
 
-fn C.sfons_create(width int, height int, flags int) &fontstash.Context
+[typedef]
+pub struct C.sfons_allocator_t {
+pub:
+	alloc     memory.FnAllocatorAlloc
+	free      memory.FnAllocatorFree
+	user_data voidptr
+}
+
+[typedef]
+pub struct C.sfons_desc_t {
+pub:
+	width     int // initial width of font atlas texture (default: 512, must be power of 2)
+	height    int // initial height of font atlas texture (default: 512, must be power of 2)
+	allocator C.sfons_allocator_t // optional memory allocation overrides
+}
+
+fn C.sfons_create(desc &C.sfons_desc_t) &fontstash.Context
 fn C.sfons_destroy(ctx &fontstash.Context)
-fn C.sfons_rgba(r u8, g u8, b u8, a u8) u32
 fn C.sfons_flush(ctx &fontstash.Context)
+
+fn C.sfons_rgba(r u8, g u8, b u8, a u8) u32