8166002: Emulate client build on platforms with reduced virtual address space

The default VM ergonomics on Windows/x86 (32-bit) are changed to client like.

Reviewed-by: kvn, iveresov

test/jtreg-ext/requires/VMProps.java

@@ -64,6 +64,7 @@ public class VMProps implements Callable<Map<String, String>> {
         map.put("vm.simpleArch", vmArch());
         map.put("vm.debug", vmDebug());
         map.put("vm.jvmci", vmJvmci());
+        map.put("vm.emulatedClient", vmEmulatedClient());
         map.put("vm.cpu.features", cpuFeatures());
         vmGC(map); // vm.gc.X = true/false
 
@@ -168,6 +169,17 @@ public class VMProps implements Callable<Map<String, String>> {
         return "" + (WB.getBooleanVMFlag("EnableJVMCI") != null);
     }
 
+    /**
+     * @return true if VM runs in emulated-client mode and false otherwise.
+     */
+    protected String vmEmulatedClient() {
+        String vmInfo = System.getProperty("java.vm.info");
+        if (vmInfo == null) {
+            return "false";
+        }
+        return "" + vmInfo.contains(" emulated-client");
+    }
+
     /**
      * @return supported CPU features
      */

test/lib/jdk/test/lib/Platform.java

@@ -63,6 +63,10 @@ public class Platform {
         return vmName.contains("Embedded");
     }
 
+    public static boolean isEmulatedClient() {
+        return vmInfo.contains(" emulated-client");
+    }
+
     public static boolean isTieredSupported() {
         return compiler.contains("Tiered Compilers");
     }