Fix legacy solid property not being set correctly when blockstate cache is invalid

Related: #244

Author: embeddedt

common/src/main/java/org/embeddedt/modernfix/common/mixin/perf/reduce_blockstate_cache_rebuilds/BlockStateBaseMixin.java

@@ -30,6 +30,7 @@ protected BlockStateBaseMixin(Block object, ImmutableMap<Property<?>, Comparable
     @Shadow private BlockBehaviour.BlockStateBase.Cache cache;
     @Shadow private FluidState fluidState;
     @Shadow private boolean isRandomlyTicking;
+    @Shadow @Deprecated private boolean legacySolid;
 
     @Shadow protected abstract BlockState asState();
 
@@ -114,4 +115,15 @@ private boolean genCacheBeforeGettingTicking(BlockBehaviour.BlockStateBase base)
             return this.owner.isRandomlyTicking(this.asState());
         return this.isRandomlyTicking;
     }
+
+    @Redirect(method = "*", at = @At(
+            value = "FIELD",
+            opcode = Opcodes.GETFIELD,
+            target = "Lnet/minecraft/world/level/block/state/BlockBehaviour$BlockStateBase;legacySolid:Z",
+            ordinal = 0
+    ))
+    private boolean genCacheBeforeCheckingSolid(BlockBehaviour.BlockStateBase base) {
+        mfix$generateCache();
+        return this.legacySolid;
+    }
 }

fabric/src/test/java/net/minecraft/world/level/block/state/BlockStateCacheTest.java

@@ -28,6 +28,9 @@ public void testCacheNullInitially() {
         BlockState stoneBlock = Blocks.STONE.defaultBlockState();
         assertTrue(((IBlockState)stoneBlock).isCacheInvalid());
         assertNull(stoneBlock.cache);
+
+        // make sure lazy cache correctly handles solid
+        assertTrue(stoneBlock.isSolid());
     }
 
     /**