Bug 572696 - [aarch64] SWT.PUSH button text alignment wrong

Update the NSTextAlignment values for Mac arm64 arch.

From Apple docs, the NSTextAlignment enumeration uses different
numerical values for some constants on arm64 and x86_64 architectures.
When referring to constants using numerical values, validate that you
use the correct values on each architecture.

Change-Id: Ia221ae6addceb0531682ac6ca406ffd9eed4524d
diff --git a/bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/org/eclipse/swt/internal/cocoa/OS.java b/bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/org/eclipse/swt/internal/cocoa/OS.java
index bc31345..fa1f248 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/org/eclipse/swt/internal/cocoa/OS.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/org/eclipse/swt/internal/cocoa/OS.java
@@ -27,6 +27,8 @@
 		return (major << 16) + (minor << 8) + bugfix;
 	}
 
+	private static final boolean IS_X86_64 = System.getProperty("os.arch").equals("x86_64"); //$NON-NLS-1$
+
 	/*
 	 *  Magic number explanation, from Cocoa's TextSizingExample:
 	 *
@@ -2298,10 +2300,10 @@
 public static final int NSTableViewSolidVerticalGridLineMask = 1;
 public static final int NSTerminateCancel = 0;
 public static final int NSTerminateNow = 1;
-public static final int NSTextAlignmentCenter = 2;
+public static final int NSTextAlignmentCenter = IS_X86_64 ? 2 : 1;
 public static final int NSTextAlignmentJustified = 3;
 public static final int NSTextAlignmentLeft = 0;
-public static final int NSTextAlignmentRight = 1;
+public static final int NSTextAlignmentRight = IS_X86_64 ? 1 : 2;
 public static final int NSTextFieldAndStepperDatePickerStyle = 0;
 public static final int NSTextFieldDatePickerStyle = 2;
 public static final int NSTitledWindowMask = 1;