Roll-forward of xcode_locator now that there are no more tools depend…

…ing on the old version.

*** Original change description ***

Support Xcode betas with xcode-locator

Previously if you had 2 builds of the same version of Xcode, for example
10.2.0 beta 1 and 10.2.0 beta 2, there was no way to disambiguate them.
This change appends the `ProductBuildVersion` of each Xcode version to
allow you to specify that if desired.

Closes #7371.

PiperOrigin-RevId: 235823433

tools/osx/xcode_locator.m

@@ -176,6 +176,14 @@ static void AddEntryToDictionary(
     NSLog(@"Version strings for %@: short=%@, expanded=%@",
           url, version, expandedVersion);
 
+    NSURL *versionPlistUrl = [url URLByAppendingPathComponent:@"Contents/version.plist"];
+    NSDictionary *versionPlistContents = [[NSDictionary alloc] initWithContentsOfURL:versionPlistUrl
+                                                                               error:nil];
+    NSString *productVersion = [versionPlistContents objectForKey:@"ProductBuildVersion"];
+    if (productVersion) {
+      expandedVersion = [expandedVersion stringByAppendingFormat:@".%@", productVersion];
+    }
+
     NSURL *developerDir =
         [url URLByAppendingPathComponent:@"Contents/Developer"];
     XcodeVersionEntry *entry =
@@ -259,12 +267,6 @@ int main(int argc, const char * argv[]) {
         versionArg = @"";
       } else {
         versionArg = firstArg;
-        NSCharacterSet *versSet =
-            [NSCharacterSet characterSetWithCharactersInString:@"0123456789."];
-        if ([versionArg rangeOfCharacterFromSet:versSet.invertedSet].length
-            != 0) {
-          versionArg = nil;
-        }
       }
     }
     if (versionArg == nil) {