add ^ (=power) and - (=unary minus) to OpenCLSubsetOpCodes

Both of these are trivial and quite common mathematical operations.
Unary minus is a bit complicated in that unary '-' is the same symbol
as binary '-' and so there needs to be a hack to expand the '-'
from the list to both of the opcodes ocSub and ocNegSub.

Change-Id: I556e20e161c22dc89919afffbf904c1ef1d552ff
Reviewed-on: https://gerrit.libreoffice.org/64362
Tested-by: Jenkins
Reviewed-by: Luboš Luňák <l.lunak@collabora.com>

officecfg/registry/schema/org/openoffice/Office/Calc.xcs

@@ -1480,7 +1480,7 @@
             true, and a formula contains only these operators and
             functions, it might be calculated using OpenCL.</desc>
           </info>
-          <value>+;-;*;/;RAND;SIN;COS;TAN;ATAN;EXP;LN;SQRT;NORMSDIST;NORMSINV;ROUND;POWER;SUMPRODUCT;MIN;MAX;SUM;PRODUCT;AVERAGE;COUNT;VAR;NORMDIST;VLOOKUP;CORREL;COVAR;PEARSON;SLOPE;SUMIFS</value>
+          <value>+;-;*;/;^;RAND;SIN;COS;TAN;ATAN;EXP;LN;SQRT;NORMSDIST;NORMSINV;ROUND;POWER;SUMPRODUCT;MIN;MAX;SUM;PRODUCT;AVERAGE;COUNT;VAR;NORMDIST;VLOOKUP;CORREL;COVAR;PEARSON;SLOPE;SUMIFS</value>
         </prop>
         <prop oor:name="OpenCLAutoSelect" oor:type="xs:boolean" oor:nillable="false">
           <info>

sc/source/core/tool/calcconfig.cxx

@@ -111,8 +111,10 @@ void ScCalcConfig::setOpenCLConfigToDefault()
     static OpCodeSet pDefaultOpenCLSubsetOpCodes(new std::set<OpCode>({
         ocAdd,
         ocSub,
+        ocNegSub,
         ocMul,
         ocDiv,
+        ocPow,
         ocRandom,
         ocSin,
         ocCos,
@@ -236,6 +238,9 @@ ScCalcConfig::OpCodeSet ScStringToOpCodeSet(const OUString& rOpCodes)
         }
         fromIndex = semicolon+1;
     }
+    // HACK: Both unary and binary minus have the same string but different opcodes.
+    if( result->find( ocSub ) != result->end())
+        result->insert( ocNegSub );
     return result;
 }