bootstrap::mlibc: link against libgcc

mlibc required libgcc to build so simply force link mlibc against
prebuilt libgcc-binaries; the alternative is to build GCC twice (which
is a tedious task).

Signed-off-by: Andy-Python-Programmer <andypythonappdeveloper@gmail.com>

Author: Andy-Python-Programmer

bootstrap.yml

@@ -47,6 +47,13 @@ sources:
           '@BUILD_ROOT@/tools/host-automake-v1.16/share/automake-1.16/config.sub',
           '@THIS_SOURCE_DIR@/mpfr-3.1.6/config.sub']
 
+  # This repository contains several precompiled freestanding libgcc.a libraries,
+  # for different architectural targets.
+  - name: libgcc-binaries
+    subdir: 'bundled'
+    git: 'https://github.com/mintsuki/libgcc-binaries.git'
+    branch: 'trunk'
+
   - name: mlibc
     subdir: 'bundled'
     git: 'https://github.com/managarm/mlibc'
@@ -815,6 +822,7 @@ packages:
     tools_required:
       - tool: host-gcc
         stage_dependencies: [compiler]
+    sources_required: ['libgcc-binaries']
     implict_package: true
     pkgs_required:
       - mlibc-headers
@@ -832,6 +840,11 @@ packages:
         - '-Dbuildtype=debug'
         - '-Dlinux_kernel_headers=@BUILD_ROOT@/packages/linux-headers/usr/include'
         - '@THIS_SOURCE_DIR@'
+        environ:
+          # mlibc requires libgcc to build so simply force link mlibc against 
+          # prebuilt libgcc-binaries; the alternative is to build GCC twice (which
+          # is a tedious task).
+          LDFLAGS: '-Wl,@THIS_SOURCE_DIR@/../libgcc-binaries/libgcc-x86_64.a'
     build:
       - args: ['ninja']
       - args: ['ninja', 'install']

patches/mlibc/mlibc.patch

@@ -1,15 +1,16 @@
-From 7ffa4a93ab4c1a5a5dd129dce1d03f784ace2e06 Mon Sep 17 00:00:00 2001
+From 40764fb1dfc0a1a0dc77f0a6b91937fc95032fd6 Mon Sep 17 00:00:00 2001
 From: Andy-Python-Programmer <andypythonappdeveloper@gmail.com>
-Date: Mon, 13 Mar 2023 16:14:34 +1100
+Date: Mon, 27 Mar 2023 20:43:27 +1100
 Subject: [PATCH] <xxx>
 
 ---
  .gitignore                            |  2 ++
- options/ansi/generic/stdlib-stubs.cpp |  6 ++++--
- options/glibc/generic/execinfo.cpp    |  5 +++--
+ meson.build                           | 42 +++++++++++++++------------
+ options/ansi/generic/stdlib-stubs.cpp |  6 ++--
+ options/glibc/generic/execinfo.cpp    |  5 ++--
  options/rtdl/generic/linker.cpp       |  2 +-
- sysdeps/aero/generic/sockets.cpp      | 25 +++++++++++++++++++++++++
- 5 files changed, 35 insertions(+), 5 deletions(-)
+ sysdeps/aero/generic/sockets.cpp      | 25 ++++++++++++++++
+ 6 files changed, 59 insertions(+), 23 deletions(-)
 
 diff --git a/.gitignore b/.gitignore
 index fdd60a0..9f811f4 100644
@@ -21,6 +22,59 @@ index fdd60a0..9f811f4 100644
  .vscode
 +# clangd cache files:
 +.cache
+diff --git a/meson.build b/meson.build
+index 2261926..3ddf806 100644
+--- a/meson.build
++++ b/meson.build
+@@ -315,24 +315,30 @@ subdir('options/bsd')
+ rtlib_deps = []
+ 
+ if not headers_only
+-	libgcc = meson.get_compiler('c').find_library('gcc', required: false)
+-
+-	compiler_rt_name = 'libclang_rt.builtins-' + host_machine.cpu_family()
+-	compiler_rt = meson.get_compiler('c').find_library(compiler_rt_name, required: false)
+-
+-	if libgcc.found()
+-		rtlib_deps += libgcc
+-	elif compiler_rt.found()
+-		rtlib_deps += compiler_rt
+-	else
+-		error('neither libgcc nor ' + compiler_rt_name + ' was found')
+-	endif
+-
+-	ld_cpp_args = [
+-		'-fvisibility=hidden',
+-		'-fno-stack-protector',
+-		'-DMLIBC_BUILDING_RTDL'
+-	]
++	# XXX: for Aero and Lyre, we force link mlibc against prebuilt 
++	# libgcc-binaries; the alternative is to build GCC twice (which
++    # is a tedious task).
++	#
++	# TODO: maybe upstream this by having a libgcc path option.
++	
++	# libgcc = meson.get_compiler('c').find_library('gcc', required: false)
++	#
++	# compiler_rt_name = 'libclang_rt.builtins-' + host_machine.cpu_family()
++	# compiler_rt = meson.get_compiler('c').find_library(compiler_rt_name, required: false)
++	#
++	# if libgcc.found()
++	# 	rtlib_deps += libgcc
++	# elif compiler_rt.found()
++	# 	rtlib_deps += compiler_rt
++	# else
++	# 	error('neither libgcc nor ' + compiler_rt_name + ' was found')
++	# endif
++	#
++	# ld_cpp_args = [
++	# 	'-fvisibility=hidden',
++	# 	'-fno-stack-protector',
++	# 	'-DMLIBC_BUILDING_RTDL'
++	# ]
+ 
+ 	libc_all_sources = [
+ 		libc_sources,
 diff --git a/options/ansi/generic/stdlib-stubs.cpp b/options/ansi/generic/stdlib-stubs.cpp
 index c0e54fe..ddeec8a 100644
 --- a/options/ansi/generic/stdlib-stubs.cpp