Fix TlsGetValue & more (#48)

`TlsGetValue` disambiguates 0 and an error by relying on `GetLastError`. Depending on the program state, `GetLastError` could be non-0, even though `TlsGetValue` succeeded. Resolve this by always setting `wibo::lastError`. This matches the behavior described by the documentation.

Additionally, when reading resources, later versions of mwcc and mwld call `GetModuleHandleA` with the program path, and then call `LoadStringA` on that handle. Support this behavior by _actually_ loading the PE at the path passed in to `GetModuleHandleA`, instead of assuming it's the current program.

(This is especially useful because sjiswrap relies on overriding `GetModuleFileNameA`, so the wrapped program reads its own resources, rather than sjiswrap's.)

Other small changes:
- Add ms-win-crt `exit` & run atexit funcs
- Implements vcruntime `memmove`
- Implements kernel32 `GetModuleFileNameA`

dll/user32.cpp

@@ -57,8 +57,7 @@ namespace user32 {
 		return (unsigned int*)(rsrcBase + langEntry);
 	}
 
-	static const char *getStringFromTable(unsigned int uID) {
-		wibo::Executable *mod = wibo::mainModule;
+	static const char *getStringFromTable(wibo::Executable *mod, unsigned int uID) {
 		unsigned int tableID = (uID >> 4) + 1;
 		unsigned int entryID = uID & 15;
 		unsigned int* stringTable = getResourceByID(mod, 6, tableID, 1033);
@@ -82,7 +81,11 @@ namespace user32 {
 
 	int WIN_FUNC LoadStringA(void* hInstance, unsigned int uID, char* lpBuffer, int cchBufferMax) {
 		DEBUG_LOG("LoadStringA %p %d %d\n", hInstance, uID, cchBufferMax);
-		const char* s = getStringFromTable(uID);
+		wibo::Executable *mod = wibo::executableFromModule(hInstance);
+		if (!mod) {
+			return 0;
+		}
+		const char* s = getStringFromTable(mod, uID);
 		if (!s) {
 			return 0;
 		}