[flang] Correct kP scaling on F output

[klausler]

Summary

The sign of the scaling factor was misinterpreted for output
as meaning what it does for input. To be correct, they
should cancel each other out.

print '(1P,F4.3)', 1. ! printed 0.1 but should print 10.0

[PeteSteinfeld]

All builds, tests, and looks good.

flang/runtime/edit-output.cpp

       return EmitPrefix(edit, converted.length, editWidth) &&
           io_.Emit(converted.str, converted.length) && EmitSuffix(edit);
     }
-    int scale{IsZero() ? -1 : edit.modes.scale};
-    int expo{converted.decimalExponent - scale};
+    int scale{IsZero() ? 1 : edit.modes.scale}; // kP
+    int expo{converted.decimalExponent + scale};
     if (expo > extraDigits && extraDigits >= 0) {
       extraDigits = expo;
       if (!edit.digits.has_value()) { // F0

flang/unittests/Runtime/hello.cpp

       {"(G32.17E4,';')", "        1.0000000000000000      ;"},
       {"(1P,E32.17,';')", "         1.00000000000000000E+00;"},
       {"(1PE32.17,';')", "         1.00000000000000000E+00;"}, // no comma
-      {"(1P,F32.17,';')", "             0.10000000000000000;"},
+      {"(1P,F32.17,';')", "            10.00000000000000000;"},
       {"(1P,G32.17,';')", "          1.0000000000000000    ;"},
       {"(ES32.17,';')", "         1.00000000000000000E+00;"},
       {"(2P,E32.17,';')", "         10.0000000000000000E-01;"},