Remove pack parsing

It was never adopted by ruby or other implementations.
Ruyb 4.1 may add new directives, so now is a good time to remove it.

It was actually never properly documented (just shows `Prism::Pack` with no methods)
so removing seems safe to do even now.

Author: Earlopain

Makefile

@@ -45,7 +45,7 @@ javascript/src/prism.wasm: Makefile $(SOURCES) $(HEADERS)
 	$(ECHO) "building $@"
 	$(Q) $(WASI_SDK_PATH)/bin/clang --sysroot=$(WASI_SDK_PATH)/share/wasi-sysroot/ \
 		$(DEBUG_FLAGS) \
-		-DPRISM_EXPORT_SYMBOLS -DPRISM_EXCLUDE_PRETTYPRINT -DPRISM_EXCLUDE_JSON -DPRISM_EXCLUDE_PACK \
+		-DPRISM_EXPORT_SYMBOLS -DPRISM_EXCLUDE_PRETTYPRINT -DPRISM_EXCLUDE_JSON \
 		-D_WASI_EMULATED_MMAN -lwasi-emulated-mman $(CPPFLAGS) $(CFLAGS) \
 		-Wl,--export-all -Wl,--gc-sections -Wl,--strip-all -Wl,--lto-O3 -Wl,--no-entry -mexec-model=reactor \
 		-Oz -g0 -flto -fdata-sections -ffunction-sections \

docs/build_system.md

@@ -113,7 +113,6 @@ MAKEFLAGS="-j10" bundle exec rake compile
 * `PRISM_ENCODING_EXCLUDE_FULL` - Will cause the library to exclude the full encoding API, and only include the minimal number of encodings to support parsing Ruby code without encoding comments. By default this is off.
 * `PRISM_EXPORT_SYMBOLS` - Will cause the shared library to export symbols. By default this is off.
 * `PRISM_EXCLUDE_JSON` - Will cause the library to exclude the JSON API. By default this is off.
-* `PRISM_EXCLUDE_PACK` - Will cause the library to exclude the pack API. By default this is off.
 * `PRISM_EXCLUDE_PRETTYPRINT` - Will cause the library to exclude the prettyprint API. By default this is off.
 * `PRISM_EXCLUDE_SERIALIZATION` - Will cause the library to exclude the serialization API. By default this is off.
 * `PRISM_XALLOCATOR` - Will cause the library to use the custom memory allocator. By default this is off.

ext/prism/api_pack.c

@@ -1434,5 +1434,4 @@ Init_prism(void) {
 
     // Next, initialize the other APIs.
     Init_prism_api_node();
-    Init_prism_pack();
 }

ext/prism/extension.c

@@ -14,7 +14,6 @@ VALUE pm_ast_new(const pm_parser_t *parser, const pm_node_t *node, rb_encoding *
 VALUE pm_integer_new(const pm_integer_t *integer);
 
 void Init_prism_api_node(void);
-void Init_prism_pack(void);
 RUBY_FUNC_EXPORTED void Init_prism(void);
 
 #endif

ext/prism/extension.h

@@ -17,7 +17,6 @@
 #include "prism/diagnostic.h"
 #include "prism/node.h"
 #include "prism/options.h"
-#include "prism/pack.h"
 #include "prism/parser.h"
 #include "prism/prettyprint.h"
 #include "prism/regexp.h"

include/prism.h

@@ -215,9 +215,6 @@
     /** Exclude the JSON serialization API. */
     #define PRISM_EXCLUDE_JSON
 
-    /** Exclude the Array#pack parser API. */
-    #define PRISM_EXCLUDE_PACK
-
     /** Exclude the prettyprint API. */
     #define PRISM_EXCLUDE_PRETTYPRINT