feat: add Java 26 Vector API demo with explanation

Signed-off-by: https://github.com/Someshdiwan <someshdiwan369@gmail.com>

Author: Someshdiwan

Java-Versions/Java 26/src/VectorApiDemo.java

@@ -0,0 +1,101 @@
+import jdk.incubator.vector.IntVector;
+import jdk.incubator.vector.VectorSpecies;
+
+public class VectorApiDemo {
+
+    static final VectorSpecies<Integer> SPECIES = IntVector.SPECIES_PREFERRED;
+
+    public static void main(String[] args) {
+
+        int[] a = {1, 2, 3, 4, 5, 6, 7, 8};
+        int[] b = {10, 20, 30, 40, 50, 60, 70, 80};
+        int[] result = new int[a.length];
+
+        addVectors(a, b, result);
+
+        System.out.println("Vector Addition Result:");
+        for (int value : result) {
+            System.out.print(value + " ");
+        }
+    }
+
+    static void addVectors(int[] a, int[] b, int[] result) {
+
+        int i = 0;
+        int upperBound = SPECIES.loopBound(a.length);
+
+        // Vectorized part
+        for (; i < upperBound; i += SPECIES.length()) {
+            var va = IntVector.fromArray(SPECIES, a, i);
+            var vb = IntVector.fromArray(SPECIES, b, i);
+            var vc = va.add(vb);
+            vc.intoArray(result, i);
+        }
+
+        // Remaining elements (scalar fallback)
+        for (; i < a.length; i++) {
+            result[i] = a[i] + b[i];
+        }
+    }
+}
+
+/*
+What changed: Previous vs New
+
+Previous Java style:
+- Used normal for-loop for array calculations
+- One element processed at a time
+- Limited CPU optimization
+
+Example:
+for (int i = 0; i < a.length; i++) {
+    result[i] = a[i] + b[i];
+}
+
+New Java 26 style:
+- Uses Vector API
+- Multiple elements processed together
+- Better use of SIMD instructions on supported CPUs
+
+Why the new approach is better:
+- Faster for large numeric workloads
+- Better CPU utilization
+- Useful in performance-heavy applications
+- Cleaner API for vectorized operations
+
+Pros:
+1. Better performance
+   - Multiple values processed in one operation
+
+2. Modern computation style
+   - Uses SIMD where hardware supports it
+
+3. Scalable
+   - Good for math-heavy programs
+
+4. Built-in API
+   - No external library needed
+
+Cons:
+1. Incubator feature
+   - Vector API is still incubating in Java 26
+
+2. More complex than simple loops
+   - Harder for beginners compared to basic for-loop
+
+3. Best for specific use cases
+   - Useful mainly in data-heavy calculations
+
+4. Requires module flag
+   - Must compile and run with incubator module enabled
+
+Best use case:
+- Image processing
+- Scientific calculations
+- Machine learning preprocessing
+- Large array computations
+
+Compile and run:
+javac --add-modules jdk.incubator.vector VectorApiDemo.java
+java --add-modules jdk.incubator.vector VectorApiDemo
+*/