Recover from error during SpEL MIXED mode compilation

Prior to this commit, SpEL was able to recover from an error that
occurred while running a CompiledExpression; however, SpEL was not able
to recover from an error that occurred while compiling the expression
(such as a java.lang.VerifyError). The latter can occur when multiple
threads concurrently change types involved in the expression, such as
the concrete type of a custom variable registered via
EvaluationContext.setVariable(...), which can result in SpEL generating
invalid bytecode.

This commit addresses this issue by catching exceptions thrown while
compiling an expression and updating the `failedAttempts` and
`interpretedCount` counters accordingly. If an exception is caught
while operating in SpelCompilerMode.IMMEDIATE mode, the exception will
be propagated via a SpelEvaluationException with a new
SpelMessage.EXCEPTION_COMPILING_EXPRESSION error category.

Closes gh-28043

spring-expression/src/test/java/org/springframework/expression/spel/standard/SpelCompilerTests.java

@@ -76,6 +76,21 @@ class SpelCompilerTests {
 		assertThat(expression.getValue(context)).asInstanceOf(BOOLEAN).isTrue();
 	}
 
+	@Test  // gh-28043
+	void changingRegisteredVariableTypeDoesNotResultInFailureInMixedMode() {
+		SpelParserConfiguration config = new SpelParserConfiguration(SpelCompilerMode.MIXED, null);
+		SpelExpressionParser parser = new SpelExpressionParser(config);
+		Expression sharedExpression = parser.parseExpression("#bean.value");
+		StandardEvaluationContext context = new StandardEvaluationContext();
+
+		Object[] beans = new Object[] {new Bean1(), new Bean2(), new Bean3(), new Bean4()};
+
+		IntStream.rangeClosed(1, 1_000_000).parallel().forEach(count -> {
+			context.setVariable("bean", beans[count % 4]);
+			assertThat(sharedExpression.getValue(context)).asString().startsWith("1");
+		});
+	}
+
 
 	static class OrderedComponent implements Ordered {
 
@@ -121,4 +136,28 @@ class SpelCompilerTests {
 		boolean hasSomeProperty();
 	}
 
+	public static class Bean1 {
+		public String getValue() {
+			return "11";
+		}
+	}
+
+	public static class Bean2 {
+		public Integer getValue() {
+			return 111;
+		}
+	}
+
+	public static class Bean3 {
+		public Float getValue() {
+			return 1.23f;
+		}
+	}
+
+	public static class Bean4 {
+		public Character getValue() {
+			return '1';
+		}
+	}
+
 }