add fs builtins

compiler/emit_js.phi

@@ -33,6 +33,10 @@
         (list "char_code" "builtinCharCode")
         (list "strings_join" "builtinStringsJoin")
         (list "get_args" "builtinGetArgs")
+        (list "fs_basename" "builtinFsBasename")
+        (list "fs_dirname" "builtinFsDirname")
+        (list "fs_cwd" "builtinFsCwd")
+        (list "fs_resolve" "builtinFsResolve")
     ))
 
     (fn generate () (do

runtime.js

@@ -1,4 +1,5 @@
 import fs from "node:fs";
+import path from "node:path";
 import process from "node:process";
 
 export class Runtime {
@@ -165,13 +166,13 @@ export class Runtime {
         return { type: "null" };
     }
 
-    builtinReadTextFile(path) {
-        const text = fs.readFileSync(path.value).toString();
+    builtinReadTextFile(filename) {
+        const text = fs.readFileSync(filename.value).toString();
         return { type: "string", value: text };
     }
 
-    builtinWriteTextFile(path, text) {
-        fs.writeFileSync(path.value, text.value);
+    builtinWriteTextFile(filename, text) {
+        fs.writeFileSync(filename.value, text.value);
         return { type: "null" };
     }
 
@@ -228,6 +229,25 @@ export class Runtime {
         };
     }
 
+    builtinFsBasename(filepath) {
+        return { type: "string", value: path.basename(filepath.value) };
+    }
+
+    builtinFsDirname(filepath) {
+        return { type: "string", value: path.dirname(filepath.value) };
+    }
+
+    builtinFsCwd() {
+        return { type: "string", value: process.cwd() };
+    }
+
+    builtinFsResolve(base, relative) {
+        return {
+            type: "string",
+            value: path.resolve(base.value, relative.value),
+        };
+    }
+
     static valueToPrint(value) {
         if (value.type === "null") {
             return "null";