Unbreak build on ppc

Fixes: https://github.com/mawww/kakoune/issues/4937

src/regex_impl.cc

@@ -83,7 +83,9 @@ struct ParsedRegex
         Quantifier quantifier;
         uint16_t filler = 0;
     };
+#ifndef __ppc__
     static_assert(sizeof(Node) == 16, "");
+#endif
 
     Vector<Node, MemoryDomain::Regex> nodes;
 

src/regex_impl.hh

@@ -131,7 +131,9 @@ struct CompiledRegex : RefCountable, UseMemoryDomain<MemoryDomain::Regex>
         mutable uint16_t last_step; // mutable as used during execution
         Param param;
     };
+#ifndef __ppc__
     static_assert(sizeof(Instruction) == 8);
+#endif
 
     explicit operator bool() const { return not instructions.empty(); }