fbc/emscripten: sizeof(wchar_t) is 4, not 2. wstring was broken.

JS strings are 16-bit (UCS2), which is where the confusion comes from.

In practice depending on exact use, using wstrings could seem to work but get
corrupted at the ends.

changelog.txt

@@ -8,6 +8,7 @@ Version 1.10.1
 [fixed]
 - sf.net #982: Array descriptors emitted incorrectly in gcc backend 
 - emscripten: fbc created faulty static libraries (it called ar instead of emar)
+- fbc: emscripten: wstring was broken because sizeof(wstring) was 2 rather than 4
 
 
 Version 1.10.0

src/compiler/fb.bas

@@ -217,7 +217,7 @@ dim shared as FBTARGET targetinfo(0 to FB_COMPTARGETS-1) = _
 	), _
 	( _
 		@"js", _
-		FB_DATATYPE_USHORT, _   '' wchar
+		FB_DATATYPE_ULONG, _   '' wchar
 		FB_FUNCMODE_CDECL, _
 		FB_FUNCMODE_STDCALL_MS, _
 		0   or FB_TARGETOPT_UNIX _