Simplify storage of JVM signatures in binary metadata

Store the whole method & field descriptor strings. Moving these strings to
separate annotation arguments later will allow to reuse them with the ones in
the constant pool, presumably allowing to save lots of space (up to 10%)

compiler/serialization/src/org/jetbrains/kotlin/serialization/StringTable.java

@@ -18,7 +18,6 @@ package org.jetbrains.kotlin.serialization;
 
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.kotlin.descriptors.ClassDescriptor;
-import org.jetbrains.kotlin.name.FqName;
 
 import java.io.OutputStream;
 
@@ -27,7 +26,5 @@ public interface StringTable {
 
     int getFqNameIndex(@NotNull ClassDescriptor descriptor);
 
-    int getFqNameIndex(@NotNull FqName fqName);
-
     void serializeTo(@NotNull OutputStream output);
 }

compiler/serialization/src/org/jetbrains/kotlin/serialization/StringTableImpl.java

@@ -91,7 +91,7 @@ public class StringTableImpl implements StringTable {
             shortName = descriptor.getName().asString();
             FqName packageFqName = ((PackageFragmentDescriptor) containingDeclaration).getFqName();
             if (!packageFqName.isRoot()) {
-                builder.setParentQualifiedName(getFqNameIndex(packageFqName));
+                builder.setParentQualifiedName(getPackageFqNameIndex(packageFqName));
             }
         }
         else if (containingDeclaration instanceof ClassDescriptor) {
@@ -109,8 +109,7 @@ public class StringTableImpl implements StringTable {
         return qualifiedNames.intern(new FqNameProto(builder));
     }
 
-    @Override
-    public int getFqNameIndex(@NotNull FqName fqName) {
+    private int getPackageFqNameIndex(@NotNull FqName fqName) {
         int result = -1;
         for (Name segment : fqName.pathSegments()) {
             QualifiedName.Builder builder = QualifiedName.newBuilder();