Fix pcodeparse.y after only the generated pcodeparse.cc was changed

311a22c038 has changed the purely
generated pcodeparse.cc instead of updating pcodeparse.y and
re-generating the source. This meant that the .y file was out of sync
with the .h file and re-generating would lead to compiler errors because
of the uintb/uint4 mismatch.

Ghidra/Features/Decompiler/src/decompile/cpp/pcodeparse.y

@@ -635,10 +635,10 @@ void PcodeLexer::initialize(istream *t)
   }
 }
 
-uintb PcodeSnippet::allocateTemp(void)
+uint4 PcodeSnippet::allocateTemp(void)
 
 { // Allocate a variable in the unique space and return the offset
-  uintb res = tempbase;
+  uint4 res = tempbase;
   tempbase += 16;
   return res;
 }