Remove unused partial specialization for MatcherMethod<T>

No matcher actually uses it, and there is no good reason for it,
as the best it can do for user is removing a single indirection
when using the pointer inside the matcher. Given the overhead of
other code that will be running during such time, it is completely
meaningless.

This also fixes compilation for PredicateMatcher<const char*>.

include/internal/catch_matchers.h

@@ -43,10 +43,6 @@ namespace Matchers {
         struct MatcherMethod {
             virtual bool match( ObjectT const& arg ) const = 0;
         };
-        template<typename PtrT>
-        struct MatcherMethod<PtrT*> {
-            virtual bool match( PtrT* arg ) const = 0;
-        };
 
 #ifdef __clang__
 #    pragma clang diagnostic pop