Fix building for FreeBSD

On FreeBSD, _assert() is a macro in <assert.h>.  The macro expansion
causes build errors like this:

	/build/source/src/LercLib/fpl_Lerc2Ext.cpp:34:6: error: expected unqualified-id
	   34 | void _assert(bool v)
	      |      ^
	/nix/store/zgvh12biq5svwz3m0s6dbcvkyrm2fbz4-libc-x86_64-unknown-freebsd-14.1.0/include/assert.h:51:22: note: expanded from macro '_assert'
	   51 | #define _assert(e)      ((void)0)
	      |                           ^
	/build/source/src/LercLib/fpl_Lerc2Ext.cpp:34:6: error: expected ')'
	/nix/store/zgvh12biq5svwz3m0s6dbcvkyrm2fbz4-libc-x86_64-unknown-freebsd-14.1.0/include/assert.h:51:22: note: expanded from macro '_assert'
	   51 | #define _assert(e)      ((void)0)
	      |                           ^
	/build/source/src/LercLib/fpl_Lerc2Ext.cpp:34:6: note: to match this '('
	/nix/store/zgvh12biq5svwz3m0s6dbcvkyrm2fbz4-libc-x86_64-unknown-freebsd-14.1.0/include/assert.h:51:21: note: expanded from macro '_assert'
	   51 | #define _assert(e)      ((void)0)
	      |                          ^
	/build/source/src/LercLib/fpl_Lerc2Ext.cpp:34:6: error: expected ')'
	   34 | void _assert(bool v)
	      |      ^
	/nix/store/zgvh12biq5svwz3m0s6dbcvkyrm2fbz4-libc-x86_64-unknown-freebsd-14.1.0/include/assert.h:51:27: note: expanded from macro '_assert'
	   51 | #define _assert(e)      ((void)0)
	      |                                ^
	/build/source/src/LercLib/fpl_Lerc2Ext.cpp:34:6: note: to match this '('
	/nix/store/zgvh12biq5svwz3m0s6dbcvkyrm2fbz4-libc-x86_64-unknown-freebsd-14.1.0/include/assert.h:51:20: note: expanded from macro '_assert'
	   51 | #define _assert(e)      ((void)0)
	      |                         ^

src/LercLib/fpl_EsriHuffman.cpp

@@ -32,7 +32,7 @@ Original coding 2021 Yuriy Yakimenko
 
 USING_NAMESPACE_LERC
 
-void _assert(bool v);
+void lerc_assert(bool v);
 
 bool decodePackBits (const unsigned char *ptr, const size_t size, size_t expected, unsigned char **output)
 {
@@ -332,7 +332,7 @@ int fpl_EsriHuffman::EncodeHuffman (const char *input, size_t input_len, unsigne
         ptr[0] = HUFFMAN_RLE; // RLE flag
         ptr[1] = input[0];
 
-        _assert(input_len <= 0xffffffff);
+        lerc_assert(input_len <= 0xffffffff);
 
         uint32_t len = (uint32_t)input_len;
 
@@ -498,7 +498,7 @@ bool fpl_EsriHuffman::DecodeHuffman(const unsigned char* inBytes, const size_t i
     {
         unsigned char *unpacked = NULL;
 
-        _assert (true == decodePackBits (ppByte + 1, inCount - 1, nBytesRemainingInOut, &unpacked));
+        lerc_assert (true == decodePackBits (ppByte + 1, inCount - 1, nBytesRemainingInOut, &unpacked));
 
         *output = unpacked;
 

src/LercLib/fpl_Lerc2Ext.cpp

@@ -32,7 +32,7 @@ Original coding 2021 Yuriy Yakimenko
 
 USING_NAMESPACE_LERC
 
-void _assert(bool v)
+void lerc_assert(bool v)
 {
   if (v == false)
     throw "Assertion failed";
@@ -65,7 +65,7 @@ static void generateListOfTestBlocks(const int width, const int height, std::vec
 {
   size_t size = (size_t)width * height;
 
-  _assert(size > 0);
+  lerc_assert(size > 0);
 
   const int block_target_size = 8 * 1024;
 
@@ -614,11 +614,11 @@ bool restoreCrossBytes(std::vector<std::pair<int, char*> >& output_buffers, cons
   //FILE* output,
   const UnitType unit_type, uint8_t** output_block)
 {
-  _assert(predictor == PREDICTOR_NONE || predictor == PREDICTOR_ROWS_COLS);
+  lerc_assert(predictor == PREDICTOR_NONE || predictor == PREDICTOR_ROWS_COLS);
 
   size_t unit_size = output_buffers.size();
 
-  _assert(unit_size == UnitTypes::size(unit_type));
+  lerc_assert(unit_size == UnitTypes::size(unit_type));
 
   const int delta = Predictor::getIntDelta(predictor);
 
@@ -670,11 +670,11 @@ bool restoreByteOrder(std::vector<std::pair<int, char*> >& output_buffers,
   const size_t cols, const size_t rows, const PredictorType predictor, //FILE* output,
   const UnitType unit_type, uint8_t** output_block)
 {
-  _assert(predictor == PREDICTOR_NONE || predictor == PREDICTOR_DELTA1);
+  lerc_assert(predictor == PREDICTOR_NONE || predictor == PREDICTOR_DELTA1);
 
   size_t unit_size = output_buffers.size();
 
-  _assert(unit_size == UnitTypes::size(unit_type));
+  lerc_assert(unit_size == UnitTypes::size(unit_type));
 
   const int delta = Predictor::getIntDelta(predictor);
 
@@ -807,7 +807,7 @@ bool LosslessFPCompression::DecodeHuffmanFltSlice (const unsigned char** ppByte,
 
     size_t extracted_size = fpl_Compression::extract_buffer((const char *)compressed, compressed_size, expected_size, &uncompressed);
 
-    _assert(expected_size == extracted_size);
+    lerc_assert(expected_size == extracted_size);
 
     free(compressed);
     compressed = NULL;