Inline MD5 instead of using a SemanticdbMd5 helper

MessageDigest is stdlib, and each plugin can express its own hex
conversion idiomatically (Kotlin one-liner via joinToString, small Java
loop). The helper added no real value beyond hiding 3 lines.

Author: jupblb

semanticdb-javac/src/main/java/com/sourcegraph/semanticdb_javac/SemanticdbVisitor.java

@@ -2,7 +2,6 @@
 
 import com.sourcegraph.semanticdb.Semanticdb;
 
-import com.sourcegraph.semanticdb.SemanticdbMd5;
 import com.sourcegraph.semanticdb.SemanticdbPaths;
 import com.sourcegraph.semanticdb.SemanticdbSymbols;
 
@@ -44,7 +43,10 @@
 import com.sourcegraph.semanticdb.Semanticdb.SymbolOccurrence.Role;
 
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Path;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
 import java.util.List;
 import java.util.ArrayList;
 import java.util.LinkedHashMap;
@@ -560,8 +562,17 @@ private String semanticdbText() {
 
   private String semanticdbMd5() {
     try {
-      return SemanticdbMd5.digest(compUnitTree.getSourceFile().getCharContent(true).toString());
-    } catch (IOException e) {
+      byte[] bytes =
+          compUnitTree
+              .getSourceFile()
+              .getCharContent(true)
+              .toString()
+              .getBytes(StandardCharsets.UTF_8);
+      byte[] digest = MessageDigest.getInstance("MD5").digest(bytes);
+      StringBuilder sb = new StringBuilder(digest.length * 2);
+      for (byte b : digest) sb.append(String.format("%02X", b));
+      return sb.toString();
+    } catch (IOException | NoSuchAlgorithmException e) {
       return "";
     }
   }

semanticdb-kotlinc/src/main/kotlin/com/sourcegraph/semanticdb_kotlinc/SemanticdbTextDocumentBuilder.kt

@@ -3,10 +3,10 @@ package com.sourcegraph.semanticdb_kotlinc
 import com.sourcegraph.semanticdb.Semanticdb
 
 import com.sourcegraph.semanticdb.Semanticdb.SymbolOccurrence.Role
-import com.sourcegraph.semanticdb.SemanticdbMd5
 import com.sourcegraph.semanticdb.SemanticdbPaths
 import java.nio.file.Path
 import java.nio.file.Paths
+import java.security.MessageDigest
 import kotlin.contracts.ExperimentalContracts
 import org.jetbrains.kotlin.KtSourceElement
 import org.jetbrains.kotlin.KtSourceFile
@@ -152,7 +152,9 @@ class SemanticdbTextDocumentBuilder(
         SemanticdbPaths.semanticdbUri(sourceroot, Paths.get(file.path))
 
     private fun semanticdbMD5(): String =
-        SemanticdbMd5.digest(file.getContentsAsStream().readBytes())
+        MessageDigest.getInstance("MD5")
+            .digest(file.getContentsAsStream().readBytes())
+            .joinToString("") { "%02X".format(it) }
 
     private fun semanticdbDocumentation(element: FirElement): Semanticdb.Documentation = Documentation {
         format = Semanticdb.Documentation.Format.MARKDOWN