Add new failing tests to help investigation

src/test/java/com/fasterxml/jackson/failing/PerfBigDecimalParser967.java

@@ -0,0 +1,37 @@
+package com.fasterxml.jackson.failing;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import com.fasterxml.jackson.core.*;
+
+// For [core#967]
+public class PerfBigDecimalParser967
+{
+    private final JsonFactory JSON_F = new JsonFactory();
+
+    // For [core#967]: shouldn't take multiple seconds
+    @Test(timeout = 35000)
+    public void bigDecimalFromString() throws Exception {
+        // Jackson's BigDecimalParser seems to be slower than JDK's;
+        // won't fail if using latter.
+        StringBuilder sb = new StringBuilder(900);
+        for (int i = 0; i < 500; ++i) {
+            sb.append('1');
+        }
+        sb.append("1e10000000");
+        final String DOC = sb.toString();
+
+        try (JsonParser p = JSON_F.createParser(DOC)) {
+            assertToken(JsonToken.VALUE_NUMBER_FLOAT, p.nextToken());
+            Assert.assertNotNull(p.getDecimalValue());
+        }
+    }
+
+    protected void assertToken(JsonToken expToken, JsonToken actToken)
+    {
+        if (actToken != expToken) {
+            Assert.fail("Expected token "+expToken+", current token "+actToken);
+        }
+    }
+}

src/test/java/com/fasterxml/jackson/failing/PerfBigDecimalToInteger968.java

@@ -0,0 +1,30 @@
+package com.fasterxml.jackson.failing;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import com.fasterxml.jackson.core.*;
+
+// For [core#968]]
+public class PerfBigDecimalToInteger968
+{
+    private final JsonFactory JSON_F = new JsonFactory();
+
+    // For [core#968]]: shouldn't take multiple seconds
+    @Test(timeout = 3000)
+    public void bigIntegerViaBigDecimal() throws Exception {
+        final String DOC = "1e20000000";
+
+        try (JsonParser p = JSON_F.createParser(DOC)) {
+            assertToken(JsonToken.VALUE_NUMBER_FLOAT, p.nextToken());
+            Assert.assertNotNull(p.getBigIntegerValue());
+        }
+    }
+
+    protected void assertToken(JsonToken expToken, JsonToken actToken)
+    {
+        if (actToken != expToken) {
+            Assert.fail("Expected token "+expToken+", current token "+actToken);
+        }
+    }
+}