Port TS PR 61082 (Fix accidental ESM-mode directory module lookup in package non-root) (#1263)

Author: jakebailey

internal/module/resolver.go

@@ -861,7 +861,7 @@ func (r *resolutionState) loadModuleFromSpecificNodeModulesDirectory(ext extensi
 			return fromDirectory
 		}
 		// !!! this is ported exactly, but checking for null seems wrong?
-		if packageInfo.Exists() &&
+		if rest == "" && packageInfo.Exists() &&
 			(packageInfo.Contents.Exports.Type == packagejson.JSONValueTypeNotPresent || packageInfo.Contents.Exports.Type == packagejson.JSONValueTypeNull) &&
 			r.esmMode {
 			// EsmMode disables index lookup in `loadNodeModuleFromDirectoryWorker` generally, however non-relative package resolutions still assume

testdata/baselines/reference/submodule/conformance/nodeModulesNoDirectoryModule.errors.txt

@@ -0,0 +1,26 @@
+/index.ts(2,8): error TS2307: Cannot find module 'i-have-a-dir-and-main/dist/dir' or its corresponding type declarations.
+
+
+==== /node_modules/i-have-a-dir-and-main/package.json (0 errors) ====
+    {
+      "name": "i-have-a-dir-and-main",
+      "version": "1.0.0",
+      "type": "module",
+      "main": "dist/index.js"
+    }
+    
+==== /node_modules/i-have-a-dir-and-main/dist/index.d.ts (0 errors) ====
+    export declare const a = 1;
+    
+==== /node_modules/i-have-a-dir-and-main/dist/dir/index.d.ts (0 errors) ====
+    export declare const b = 2;
+    
+==== /package.json (0 errors) ====
+    { "type": "module" }
+    
+==== /index.ts (1 errors) ====
+    import 'i-have-a-dir-and-main' // ok
+    import 'i-have-a-dir-and-main/dist/dir' // error
+           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2307: Cannot find module 'i-have-a-dir-and-main/dist/dir' or its corresponding type declarations.
+