message: Remove memory allocation from ImportText
diff: #include "mldb/jml/utils/vector_utils.h"
  #include "mldb/utils/log.h"
  #include "mldb/ext/re2/re2/re2.h"
  +#include "mldb/utils/possibly_dynamic_buffer.h"
  using namespace std;
  @@ -1084,14 +1085,14 @@ struct ImportTextProcedureWorkInstance
  // TODO: clang doesn't like a variable length array
  // here. Find another way to allocate it on the
  // stack.
  - vector<CellValue> values(inputColumnNames.size());
  + PossiblyDynamicBuffer<CellValue> values(inputColumnNames.size());
  const char * lineStart = line;
  const size_t numInputColumn = inputColumnNames.size();
  const char * errorMsg
  - = parseFixedWidthCsvRow(line, length, &values[0],
  + = parseFixedWidthCsvRow(line, length, values.data(),
  numInputColumn,
  separator, quote, encoding,
  replaceInvalidCharactersWith,
  @@ -1115,7 +1116,7 @@ struct ImportTextProcedureWorkInstance
  string(line, length));
  }
  - auto row = scope.bindRow(&values[0], ts, actualLineNum,
  + auto row = scope.bindRow(values.data(), ts, actualLineNum,
  0 /* todo: chunk ofs */);
  ExpressionValue nameStorage;
  