[metadata] split IL generation code into seperate compilation units. (mono/mono#7487)

* [metadata] split IL generation code into seperate compilation units.

* [metadata] move ENABLE_ILGEN definition to configure

* [metadata] split IL generation code into seperate compilation units.

By adding callbacks for IL generating runtime code, we can link in code
later into the runtime that does such for configurations which do not
need IL generation initially. This is the case if you configure the
runtime with `--enable-minimal=jit,interpreter`.

In such configuration, the build will produce an additional library,
called `libmono-ilgen`.

An embedded can choose to link this library to the final binary and
initialize IL generation with the following three, newly added, API
calls:

* `void mono_marshal_ilgen_init (void)`
* `void mono_method_builder_ilgen_init (void)`
* `void mono_sgen_mono_ilgen_init (void)`

This change is mostly moving code around, but there are minor changes
like introducing the enum `MarshalTypeCheckPositions`, so we avoid
copy/paste constants accross compilation units.

* [windows] add IL gen files to windows build and set ENABLE_ILGEN

* [fixup!] fix windows build

* [fixup!] resolve merge conflicts with class getter commits

* marshal.c: mono/mono@b8da973
* sgen-mono.c: mono/mono@8ba4947

at some point I gave up to resolve merge conflicts and worked through
errors/warnings by compiling with
> `CFLAGS=-DENABLE_CHECKED_BUILD_PRIVATE_TYPES=1`
so the result is likely a bit different

* redo lost changes from mono/mono@57f3f34

* redo lost changes from mono/mono@52514ef

* [fixup!] fix array marshal

* [method-builder] use eglib types

review comment by Ludovic,
mono/mono#7375 (comment)

* [marshal] remove stelem strings from header

review comment by Rodrigo,
mono/mono#7375 (comment)


Commit migrated from mono/mono@868a402

Author: lewurm

src/mono/configure.ac

@@ -1422,6 +1422,12 @@ fi
 
 AM_CONDITIONAL(DISABLE_INTERPRETER, test x$mono_feature_disable_interpreter = xyes)
 
+if test "x$mono_feature_disable_interpreter" != "xyes" -o "x$mono_feature_disable_jit" != "xyes"; then
+	AC_DEFINE(ENABLE_ILGEN, 1, [Some VES is available at runtime])
+fi
+
+AM_CONDITIONAL(ENABLE_ILGEN, test x$mono_feature_disable_interpreter != xyes -o x$mono_feature_disable_jit != xyes)
+
 if test "x$mono_feature_disable_simd" = "xyes"; then
 	AC_DEFINE(DISABLE_SIMD, 1, [Disable SIMD intrinsics related optimizations.])
 	AC_MSG_NOTICE([Disabled SIMD support])

src/mono/mono/metadata/Makefile.am

@@ -85,9 +85,13 @@ if DISABLE_ICALL_TABLES
 icall_table_libraries = libmono-icall-table.la
 endif
 
+if !ENABLE_ILGEN
+ilgen_libraries = libmono-ilgen.la
+endif
+
 noinst_LTLIBRARIES = libmonoruntime-config.la $(boehm_libraries) $(sgen_libraries)
 
-lib_LTLIBRARIES = $(icall_table_libraries)
+lib_LTLIBRARIES = $(icall_table_libraries) $(ilgen_libraries)
 
 AM_CPPFLAGS = -I$(top_srcdir) -I$(top_srcdir)/mono $(LIBGC_CPPFLAGS) $(GLIB_CFLAGS) $(SHARED_CFLAGS)
 
@@ -122,6 +126,25 @@ libmono_icall_table_la_LIBADD = ../eglib/libeglib.la ../utils/libmonoutils.la ..
 endif
 endif
 
+#
+# This library contains code to generate IL at runtime
+#
+if !ENABLE_ILGEN
+libmono_ilgen_la_SOURCES = \
+	method-builder-ilgen.c \
+	method-builder-ilgen.h \
+	method-builder-ilgen-internals.h \
+	marshal-ilgen.c \
+	marshal-ilgen.h	\
+	sgen-mono-ilgen.c \
+	sgen-mono-ilgen.h
+libmono_ilgen_la_CFLAGS = $(SGEN_DEFINES)
+libmono_ilgen_la_LDFLAGS = $(libmonoldflags)
+if BITCODE
+libmono_ilgen_la_LIBADD = ../eglib/libeglib.la ../utils/libmonoutils.la ../sgen/libmonosgen.la libmonoruntimesgen.la
+endif
+endif
+
 CLEANFILES = mono-bundle.stamp
 
 null_sources = \
@@ -137,6 +160,17 @@ icall_tables_sources = \
 	icall-table.c
 endif
 
+if ENABLE_ILGEN
+ilgen_sources = \
+	method-builder-ilgen.c \
+	method-builder-ilgen.h \
+	method-builder-ilgen-internals.h \
+	marshal-ilgen.c \
+	marshal-ilgen.h	\
+	sgen-mono-ilgen.c \
+	sgen-mono-ilgen.h
+endif
+
 common_sources = \
 	$(platform_sources)	\
 	appdomain.c	\
@@ -204,6 +238,7 @@ common_sources = \
 	metadata-verify.c	\
 	metadata-internals.h	\
 	method-builder.h 	\
+	method-builder-internals.h 	\
 	method-builder.c 	\
 	mono-basic-block.c	\
 	mono-basic-block.h	\
@@ -327,13 +362,14 @@ sgen_sources = \
 	sgen-toggleref.h		\
 	sgen-stw.c				\
 	sgen-mono.c		\
+	sgen-mono.h		\
 	sgen-client-mono.h
 
-libmonoruntime_la_SOURCES = $(common_sources) $(icall_tables_sources) $(gc_dependent_sources) $(null_gc_sources) $(boehm_sources)
+libmonoruntime_la_SOURCES = $(common_sources) $(icall_tables_sources) $(ilgen_sources) $(gc_dependent_sources) $(null_gc_sources) $(boehm_sources)
 libmonoruntime_la_CFLAGS = $(BOEHM_DEFINES)
 libmonoruntime_la_LIBADD = libmonoruntime-config.la
 
-libmonoruntimesgen_la_SOURCES = $(common_sources) $(icall_tables_sources) $(gc_dependent_sources) $(sgen_sources)
+libmonoruntimesgen_la_SOURCES = $(common_sources) $(icall_tables_sources) $(ilgen_sources) $(gc_dependent_sources) $(sgen_sources)
 libmonoruntimesgen_la_CFLAGS = $(SGEN_DEFINES)
 libmonoruntimesgen_la_LIBADD = libmonoruntime-config.la
 

src/mono/mono/metadata/boehm-gc.c

@@ -18,6 +18,8 @@
 #include <mono/metadata/profiler-private.h>
 #include <mono/metadata/class-internals.h>
 #include <mono/metadata/method-builder.h>
+#include <mono/metadata/method-builder-ilgen.h>
+#include <mono/metadata/method-builder-ilgen-internals.h>
 #include <mono/metadata/opcodes.h>
 #include <mono/metadata/domain-internals.h>
 #include <mono/metadata/metadata-internals.h>

src/mono/mono/metadata/cominterop.c

@@ -29,6 +29,7 @@
 #include "mono/metadata/threads.h"
 #include "mono/metadata/monitor.h"
 #include "mono/metadata/metadata-internals.h"
+#include "mono/metadata/method-builder-ilgen-internals.h"
 #include "mono/metadata/domain-internals.h"
 #include "mono/metadata/gc-internals.h"
 #include "mono/metadata/threads-types.h"

src/mono/mono/metadata/cominterop.h

@@ -11,6 +11,7 @@
 #define __MONO_COMINTEROP_H__
 
 #include <mono/metadata/method-builder.h>
+#include <mono/metadata/method-builder-ilgen.h>
 #include <mono/metadata/marshal.h>
 
 void