Use absolute file path when symbolicating HBC bundles

Summary:
Changelog: [Internal]

When enabling Metro with bytecode for apps like Twilight, we're seeing these type of error:
```
Error: ENOENT: no such file or directory, open 'RKJSModules/vendor/react/cjs/React-dev.js'
    at Object.openSync (fs.js:457:3)
    at Object.readFileSync (fs.js:359:35)
    at getCodeFrame (/Users/keo/Library/Caches/dotslash/obj/everstore/f7/GCF5agem2GP1NT0DACsCkMSaYsFCblMqAAAA/extract/tar.gz/metro/src/Server.js:1013:401)
    at Server._symbolicate (/Users/keo/Library/Caches/dotslash/obj/everstore/f7/GCF5agem2GP1NT0DACsCkMSaYsFCblMqAAAA/extract/tar.gz/metro/src/Server.js:1062:20)
    at runMicrotasks (<anonymous>)
    at processTicksAndRejections (internal/process/task_queues.js:97:5)
    at async Server._processRequest (/Users/keo/Library/Caches/dotslash/obj/everstore/f7/GCF5agem2GP1NT0DACsCkMSaYsFCblMqAAAA/extract/tar.gz/metro/src/Server.js:993:408)
```

This diff ensures we resolve the file to an absolute path and surrounds the `readFileSync` call with a try/catch to make sure we don't hit these errors.

Reviewed By: cpojer

Differential Revision: D25262626

fbshipit-source-id: 5d53e3ccd1942d44beb3873bf3450e7668b0dc29

packages/metro/src/Server.js

@@ -988,25 +988,30 @@ class Server {
     const getCodeFrame = (urls, symbolicatedStack) => {
       for (let i = 0; i < symbolicatedStack.length; i++) {
         const {collapse, column, file, lineNumber} = symbolicatedStack[i];
-        if (collapse || lineNumber == null || urls.has(file)) {
+        const entryPoint = path.resolve(this._config.projectRoot, file);
+        if (collapse || lineNumber == null || urls.has(entryPoint)) {
           continue;
         }
 
-        return {
-          content: codeFrameColumns(
-            fs.readFileSync(file, 'utf8'),
-            {
-              // Metro returns 0 based columns but codeFrameColumns expects 1-based columns
-              start: {column: column + 1, line: lineNumber},
+        try {
+          return {
+            content: codeFrameColumns(
+              fs.readFileSync(entryPoint, 'utf8'),
+              {
+                // Metro returns 0 based columns but codeFrameColumns expects 1-based columns
+                start: {column: column + 1, line: lineNumber},
+              },
+              {forceColor: true},
+            ),
+            location: {
+              row: lineNumber,
+              column,
             },
-            {forceColor: true},
-          ),
-          location: {
-            row: lineNumber,
-            column,
-          },
-          fileName: file,
-        };
+            fileName: file,
+          };
+        } catch (error) {
+          console.error(error);
+        }
       }
 
       return null;