Compute offsets from startOffset

Author: msimacek

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/compiler/CodeUnit.java

@@ -126,7 +126,7 @@ OpCodes codeForBC(int bc) {
 
     public int bciToSrcOffset(int bci) {
         int diffIdx = 0;
-        int currentOffset = 0;
+        int currentOffset = startOffset;
 
         int bytecodeNumber = 0;
         for (int i = 0; i < code.length;) {

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/compiler/CompilationUnit.java

@@ -196,7 +196,7 @@ public CodeUnit assemble(int flags) {
 
         Block b = startBlock;
         HashMap<Block, List<Block>> handlerBlocks = new HashMap<>();
-        int lastSrcOffset = 0;
+        int lastSrcOffset = startOffset;
         while (b != null) {
             b.startBci = buf.size();
             BlockInfo.AbstractExceptionHandler handler = b.findExceptionHandler();