refactor: redesign GPU support

- unify CPU and GPU bootstrapping operations
- remove operations to build GLWE from table: this is now done in
  wrapper functions
- remove GPU memory management operations: done in wrappers now, but we
  will have to think about how to deal with it later in MLIR

compiler/src/main.cpp

@@ -98,11 +98,11 @@ llvm::cl::opt<bool>
                                     "dialects. (Enabled by default)"),
                      llvm::cl::init<bool>(true));
 
-llvm::cl::opt<bool>
-    useGPU("use-gpu",
-           llvm::cl::desc("enable/disable generating concrete GPU "
-                          "operations (Disabled by default)"),
-           llvm::cl::init<bool>(false));
+llvm::cl::opt<bool> useGPU(
+    "use-gpu",
+    llvm::cl::desc(
+        "enable/disable generating GPU operations (Disabled by default)"),
+    llvm::cl::init<bool>(false));
 
 llvm::cl::list<std::string> passes(
     "passes",