Add enablePrattParser option and split Parser into AntlrParser and dispatcher

Split Parser.java into AntlrParser.java (containing all ANTLR dependencies) and Parser.java (acting as a simple dispatcher between AntlrParser and PrattParser).
Refactor CelParserParameterizedTest and CelParserImplTest to run tests against both ANTLR and Pratt parsers to ensure exact AST equivalence.

PiperOrigin-RevId: 978827922

Author: dmitriplotnikov

common/src/main/java/dev/cel/common/CelOptions.java

@@ -72,6 +72,8 @@ public enum ProtoUnsetFieldOptions {
 
   public abstract boolean enableQuotedIdentifierSyntax();
 
+  public abstract boolean enablePrattParser();
+
   // Type-Checker related options
 
   public abstract boolean enableCompileTimeOverloadResolution();
@@ -144,6 +146,7 @@ public static Builder newBuilder() {
         .retainUnbalancedLogicalExpressions(false)
         .enableHiddenAccumulatorVar(true)
         .enableQuotedIdentifierSyntax(true)
+        .enablePrattParser(false)
         // Type-Checker options
         .enableCompileTimeOverloadResolution(false)
         .enableHomogeneousLiterals(false)
@@ -279,6 +282,14 @@ public abstract static class Builder {
      */
     public abstract Builder enableQuotedIdentifierSyntax(boolean value);
 
+    /**
+     * Enables Pratt parser implementation over ANTLR parser.
+     *
+     * <p>The Pratt parser provides improved parsing performance (typically 4x–11x speedup over
+     * ANTLR) and lower memory overhead while producing an equivalent abstract syntax tree.
+     */
+    public abstract Builder enablePrattParser(boolean value);
+
     // Type-Checker related options
 
     /**

common/src/test/java/dev/cel/common/CelOptionsTest.java

@@ -35,5 +35,6 @@ public void current_defaults() {
     // Defaults that aren't represented in deprecated CelOptions
     assertThat(CelOptions.current().build().enableUnknownTracking()).isFalse();
     assertThat(CelOptions.current().build().resolveTypeDependencies()).isTrue();
+    assertThat(CelOptions.current().build().enablePrattParser()).isFalse();
   }
 }

extensions/src/test/java/dev/cel/extensions/CelMathExtensionsTest.java

@@ -827,7 +827,7 @@ public void abs_overflow_throwsException() {
 
     assertThat(e)
         .hasMessageThat()
-        .contains("ERROR: <input>:1:10: For input string: \"-9223372036854775809\"");
+        .contains("ERROR: <input>:1:10: invalid int literal: -9223372036854775809");
   }
 
   @Test
@@ -917,7 +917,7 @@ public void bitAnd_maxValArg_throwsException() {
 
     assertThat(e)
         .hasMessageThat()
-        .contains("ERROR: <input>:1:33: For input string: \"9223372036854775809\"");
+        .contains("ERROR: <input>:1:33: invalid int literal: 9223372036854775809");
   }
 
   @Test