Mark param_max_combine_insns with Optimization keyword.

    PR tree-optimization/92860
    * params.opt: Mark param_max_combine_insns with Optimization
    keyword.

From-SVN: r279895

gcc/ChangeLog

+2020-01-06  Martin Liska  <mliska@suse.cz>
+
+    PR tree-optimization/92860
+    * params.opt: Mark param_max_combine_insns with Optimization
+    keyword. 
+
 2020-01-05  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/93141

gcc/params.opt

@@ -375,7 +375,7 @@ Common Joined UInteger Var(param_max_average_unrolled_insns) Init(80) Param
 The maximum number of instructions to consider to unroll in a loop on average.
 
 -param=max-combine-insns=
-Common Joined UInteger Var(param_max_combine_insns) Init(4) IntegerRange(2, 4) Param
+Common Joined UInteger Var(param_max_combine_insns) Init(4) IntegerRange(2, 4) Param Optimization
 The maximum number of insns combine tries to combine.
 
 -param=max-completely-peel-loop-nest-depth=