Remove superfluous nqp::ln_n op from all three backends.

Author: arnsholt

src/vm/jvm/QAST/Compiler.nqp

@@ -1995,7 +1995,6 @@ QAST::OperationsJAST.map_classlib_core_op('abs_n', $TYPE_MATH, 'abs', [$RT_NUM],
 
 QAST::OperationsJAST.map_classlib_core_op('ceil_n', $TYPE_MATH, 'ceil', [$RT_NUM], $RT_NUM);
 QAST::OperationsJAST.map_classlib_core_op('floor_n', $TYPE_MATH, 'floor', [$RT_NUM], $RT_NUM);
-QAST::OperationsJAST.map_classlib_core_op('ln_n', $TYPE_MATH, 'log', [$RT_NUM], $RT_NUM);
 QAST::OperationsJAST.map_classlib_core_op('sqrt_n', $TYPE_MATH, 'sqrt', [$RT_NUM], $RT_NUM);
 QAST::OperationsJAST.map_classlib_core_op('log_n', $TYPE_MATH, 'log', [$RT_NUM], $RT_NUM);
 QAST::OperationsJAST.map_classlib_core_op('exp_n', $TYPE_MATH, 'exp', [$RT_NUM], $RT_NUM);

src/vm/moar/QAST/QASTOperationsMAST.nqp

@@ -1813,7 +1813,6 @@ QAST::MASTOperations.add_core_moarop_mapping('abs_I', 'abs_I');
 QAST::MASTOperations.add_core_moarop_mapping('abs_n', 'abs_n');
 QAST::MASTOperations.add_core_moarop_mapping('ceil_n', 'ceil_n');
 QAST::MASTOperations.add_core_moarop_mapping('floor_n', 'floor_n');
-QAST::MASTOperations.add_core_moarop_mapping('ln_n', 'log_n'); # looks like this one is never used
 QAST::MASTOperations.add_core_moarop_mapping('sqrt_n', 'sqrt_n');
 QAST::MASTOperations.add_core_moarop_mapping('base_I', 'base_I');
 QAST::MASTOperations.add_core_moarop_mapping('isbig_I', 'isbig_I');

src/vm/parrot/QAST/Operations.nqp

@@ -1854,7 +1854,6 @@ QAST::Operations.add_core_pirop_mapping('lcm_I', 'nqp_bigint_lcm', 'PPPP', :inli
 
 QAST::Operations.add_core_pirop_mapping('ceil_n', 'ceil', 'Nn', :inlinable(1));
 QAST::Operations.add_core_pirop_mapping('floor_n', 'floor', 'NN', :inlinable(1));
-QAST::Operations.add_core_pirop_mapping('ln_n', 'ln', 'Nn', :inlinable(1));
 QAST::Operations.add_core_pirop_mapping('sqrt_n', 'sqrt', 'Nn', :inlinable(1));
 QAST::Operations.add_core_pirop_mapping('radix', 'nqp_radix', 'Pisii', :inlinable(1));
 QAST::Operations.add_core_pirop_mapping('radix_I', 'nqp_bigint_radix', 'PisiiP', :inlinable(1));