Lute check uses the new solver by default (#711)

Addresses #710 

Updates `lute check` to use the new solver by default.

Fails the test as expected without the change
```
Failed Tests (1):

❌ lute check.uses new solver
	/Users/rng/dev/lute/tests/cli/check.test.luau:32
		eq: 1 ~= 0
```

Author: raymondnumbergenerator

lute/cli/src/tc.cpp

@@ -8,31 +8,6 @@
 #include "Luau/FileUtils.h"
 #include "Luau/Frontend.h"
 
-static const std::string kLuteDefinitions = R"LUTE_TYPES(
--- Net api
-declare net: {
-    get: (string) -> string,
-    getAsync: (string) -> string,
-}
--- fs api
-declare class file end
-declare fs: {
- -- probably not the correct sig
-    open: (string, "r" | "w" | "a" | "r+" | "w+") -> file,
-    close: (file) -> (),
-    read: (file) -> string,
-    write: (file, string) -> (),
-    readfiletostring : (string) -> string,
-    writestringtofile : (string, string) -> (),
- -- is this right? I feel like we want a promise type here
-    readasync : (string) -> string,
-}
-
--- globals
-declare function spawn(path: string): any
-
-)LUTE_TYPES";
-
 struct LuteFileResolver : Luau::LuteModuleResolver
 {
     std::optional<Luau::SourceCode> readSource(const Luau::ModuleName& name) override
@@ -186,11 +161,9 @@ int typecheck(const std::vector<std::string>& sourceFilesInput, LuteReporter& re
     LuteFileResolver fileResolver;
     Luau::LuteConfigResolver configResolver(mode);
     Luau::Frontend frontend(&fileResolver, &configResolver, frontendOptions);
+    frontend.setLuauSolverMode(Luau::SolverMode::New);
 
     Luau::registerBuiltinGlobals(frontend, frontend.globals);
-    Luau::LoadDefinitionFileResult loadResult =
-        frontend.loadDefinitionFile(frontend.globals, frontend.globals.globalScope, kLuteDefinitions, "@luau", false, false);
-    LUAU_ASSERT(loadResult.success);
     Luau::freeze(frontend.globals.globalTypes);
 
     for (const std::string& path : sourceFiles)

tests/CMakeLists.txt

@@ -24,7 +24,8 @@ target_sources(Lute.Test PRIVATE
     src/packagerequire.test.cpp
     src/require.test.cpp
     src/staticrequires.test.cpp
-    src/stdsystem.test.cpp)
+    src/stdsystem.test.cpp
+    src/typecheck.test.cpp)
 
 set_target_properties(Lute.Test PROPERTIES OUTPUT_NAME lute-tests)
 target_compile_features(Lute.Test PUBLIC cxx_std_17)

tests/cli/check.test.luau

@@ -0,0 +1,16 @@
+local fs = require("@std/fs")
+local path = require("@std/path")
+local process = require("@std/process")
+local system = require("@std/system")
+local test = require("@std/test")
+
+local lutePath = path.format(process.execpath())
+
+test.suite("LuteTypeCheck", function(suite)
+	suite:case("UsesNewSolver", function(assert)
+		local testFilePath = path.format(path.join("tests", "src", "staticrequires", "newsolver.luau"))
+
+		local result = process.run({ lutePath, "check", testFilePath })
+		assert.eq(result.exitcode, 0)
+	end)
+end)

tests/src/staticrequires/newsolver.luau

@@ -0,0 +1,14 @@
+-- This file should fail the old solver
+function add(a, b)
+	return a + b
+end
+local vec2 = {}
+function vec2.new(x, y)
+	return setmetatable({ x = x or 0, y = y or 0 }, {
+		__add = function(v1, v2)
+			return { x = v1.x + v2.x, y = v1.y + v2.y }
+		end,
+	})
+end
+add(1, 1)
+add(vec2.new(0, 0), vec2.new(1, 1))

tests/src/typecheck.test.cpp

@@ -0,0 +1,16 @@
+#include "lute/tc.h"
+
+#include "Luau/FileUtils.h"
+
+#include "doctest.h"
+#include "lutefixture.h"
+#include "luteprojectroot.h"
+
+TEST_CASE_FIXTURE(LuteFixture, "typecheck_uses_new_solver")
+{
+    std::string luteProjectRoot = getLuteProjectRootAbsolute();
+    std::string testFilePath = joinPaths(luteProjectRoot, "tests/src/staticrequires/newsolver.luau");
+
+    auto result = typecheck({testFilePath}, getReporter());
+    CHECK(result == 0);
+}