[PECOFF] Set OrdinalBase field in the export table.

OrdinalBase is an addend to the ordinals. We used to always set 1 to the field.
Although it produced a valid a DLL export table, it'd be a waste if the first
ordinal does not start with 1 -- we had to have NULL fields at the beginning of
the export address table. By setting the ordinal base, we can eliminate the
NULL fields.
clang-format: Improve handling of raw string literals.

Especially try to keep existing line breaks before raw string literals,
as the code author might have aligned content to it.

Thereby, clang-format now keeps things like:

  parseStyle(R"(
      BasedOnStyle: Google,
      ColumnLimit: 100)");
  parseStyle(
      R"(BasedOnStyle: Google,
         ColumnLimit: 100)");