[flang][runtime] Fix total MAXLOC/MINLOC for non-integer data

[klausler]

Summary

A template argument was hard-coded as the Integer type category
rather than properly forwarding the type category of the data for
type-specific instantiations of total (no DIM=) MAXLOC and MINLOC.
This broke total MAXLOC and MINLOC reductions for real and character
data.

[clementval]

LGTM

flang/runtime/extrema.cpp

     void operator()(const char *intrinsic, Descriptor &result,
         const Descriptor &x, int kind, const char *source, int line,
         const Descriptor *mask, bool back) const {
-      DoMaxOrMinLoc<TypeCategory::Integer, KIND, IS_MAX, NumericCompare>(
+      DoMaxOrMinLoc<CAT, KIND, IS_MAX, NumericCompare>(
           intrinsic, result, x, kind, source, line, mask, back);
     }
   };