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`

main.cpp

@@ -31,7 +31,7 @@ void wibo::debug_log(const char *fmt, ...) {
 
 		vfprintf(stderr, fmt, args);
 	}
-	
+
 	va_end(args);
 }
 
@@ -110,11 +110,6 @@ const wibo::Module * wibo::modules[] = {
 	nullptr,
 };
 
-struct ModuleInfo {
-	std::string name;
-	const wibo::Module* module = nullptr;
-};
-
 HMODULE wibo::loadModule(const char *dllName) {
 	auto *result = new ModuleInfo;
 	result->name = dllName;
@@ -151,6 +146,32 @@ void *wibo::resolveFuncByOrdinal(HMODULE module, uint16_t ordinal) {
 	return resolveMissingFuncOrdinal(info->name.c_str(), ordinal);
 }
 
+wibo::Executable *wibo::executableFromModule(HMODULE module) {
+	if (wibo::isMainModule(module)) {
+		return wibo::mainModule;
+	}
+
+	auto info = static_cast<wibo::ModuleInfo *>(module);
+	if (!info->executable) {
+		DEBUG_LOG("wibo::executableFromModule: loading %s\n", info->name.c_str());
+		auto executable = std::make_unique<wibo::Executable>();
+		const auto path = files::pathFromWindows(info->name.c_str());
+		FILE *f = fopen(path.c_str(), "rb");
+		if (!f) {
+			perror("wibo::executableFromModule");
+			return nullptr;
+		}
+		bool result = executable->loadPE(f, false);
+		fclose(f);
+		if (!result) {
+			DEBUG_LOG("wibo::executableFromModule: failed to load %s\n", path.c_str());
+			return nullptr;
+		}
+		info->executable = std::move(executable);
+	}
+	return info->executable.get();
+}
+
 struct UNICODE_STRING {
 	unsigned short Length;
 	unsigned short MaximumLength;
@@ -295,7 +316,7 @@ int main(int argc, char **argv) {
 		return 1;
 	}
 
-	exec.loadPE(f);
+	exec.loadPE(f, true);
 	fclose(f);
 
 	// 32-bit windows only reserves the lowest 2GB of memory for use by a process (https://www.tenouk.com/WinVirtualAddressSpace.html)