Fix the reported line/column for syntax errors.

As reported at decaffeinate/decaffeinate#54, CoffeeScriptRedux syntax
errors always point to line 1 column 1. This is very annoying when
trying to figure out what part of the file it actually can’t parse.
This updates the peg override to match the new signature for
`peg$computePosDetails` which now takes a `pos` argument.

src/grammar.pegcoffee

@@ -272,36 +272,37 @@
  return peg$reportedPos - csr$controlCharacterCount;
  }
 
- function peg$computePosDetails() {
- function advanceCachedReportedPos() {
- var ch;
+ function peg$computePosDetails(pos) {
+ function advance(details, startPos, endPos) {
+ var p, ch;
 
- for (; peg$cachedPos < peg$reportedPos; peg$cachedPos++) {
- ch = input.charAt(peg$cachedPos);
+ for (p = startPos; p < endPos; p++) {
+ ch = input.charAt(p);
  if (ch === "\n") {
- if (!peg$cachedPosDetails.seenCR) { peg$cachedPosDetails.line++; }
- peg$cachedPosDetails.column = 1;
- peg$cachedPosDetails.seenCR = false;
+ if (!details.seenCR) { details.line++; }
+ details.column = 1;
+ details.seenCR = false;
  } else if (ch === "\r" || ch === "\u2028" || ch === "\u2029") {
- peg$cachedPosDetails.line++;
- peg$cachedPosDetails.column = 1;
- peg$cachedPosDetails.seenCR = true;
+ details.line++;
+ details.column = 1;
+ details.seenCR = true;
  } else if(!/[\uEFEF\uEFFE\uEFFF]/.test(ch)) {
- peg$cachedPosDetails.column++;
- peg$cachedPosDetails.seenCR = false;
+ details.column++;
+ details.seenCR = false;
  } else {
  csr$controlCharacterCount++;
  }
  }
  }
 
- if (peg$cachedPos !== peg$reportedPos) {
- if (peg$cachedPos > peg$reportedPos) {
+ if (peg$cachedPos !== pos) {
+ if (peg$cachedPos > pos) {
  csr$controlCharacterCount = 0;
  peg$cachedPos = 0;
  peg$cachedPosDetails = { line: 1, column: 1, seenCR: false };
  }
- advanceCachedReportedPos();
+ advance(peg$cachedPosDetails, peg$cachedPos, pos);
+ peg$cachedPos = pos;
  }
 
  return peg$cachedPosDetails;