dev-libs/libffi: backport further patches (arm64 + BTI/PAC, ASAN)

I should've done this earlier in -r1 but I equivocated.

Signed-off-by: Sam James <[email protected]>

dev-libs/libffi/files/libffi-3.4.6-arm64-bti-spelling.patch

@@ -0,0 +1,26 @@
+https://github.com/libffi/libffi/commit/38732240c125b6af9db66d940c0725a69292cc49
+
+From 38732240c125b6af9db66d940c0725a69292cc49 Mon Sep 17 00:00:00 2001
+From: Bill Roberts <[email protected]>
+Date: Sat, 1 Jun 2024 12:33:28 -0500
+Subject: [PATCH] ffi: fix spelling mistake (#833)
+
+Signed-off-by: Bill Roberts <[email protected]>
+---
+ src/aarch64/ffi.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/src/aarch64/ffi.c b/src/aarch64/ffi.c
+index 8661a352..b13738e3 100644
+--- a/src/aarch64/ffi.c
++++ b/src/aarch64/ffi.c
+@@ -682,7 +682,7 @@ ffi_call_int (ffi_cif *cif, void (*fn)(void), void *orig_rvalue,
+   else if (flags & AARCH64_RET_NEED_COPY)
+     rsize = 16;
+
+-  /* Allocate consectutive stack for everything we'll need.
++  /* Allocate consecutive stack for everything we'll need.
+      The frame uses 40 bytes for: lr, fp, rvalue, flags, sp */
+   context = alloca (sizeof(struct call_context) + stack_bytes + 40 + rsize);
+   stack = context + 1;
+

dev-libs/libffi/files/libffi-3.4.6-arm64-bti.patch

@@ -0,0 +1,81 @@
+https://github.com/libffi/libffi/commit/f64141ee3f9e455a060bd09e9ab72b6c94653d7c
+
+From f64141ee3f9e455a060bd09e9ab72b6c94653d7c Mon Sep 17 00:00:00 2001
+From: Bill Roberts <[email protected]>
+Date: Tue, 19 Mar 2024 11:44:55 -0500
+Subject: [PATCH] Fix bti support (#830)
+
+* bti: add identifier to ffi_closure_SYSV_V_alt
+
+This was missing BTI_C identifier.
+
+Old Code:
+ffi_closure_SYSV_V_alt:
+0000fffff7f70500:   ldr     x17, [sp, #8]
+
+Signed-off-by: Bill Roberts <[email protected]>
+
+* testsuite: fix whitespace in Makefile.am
+
+Signed-off-by: Bill Roberts <[email protected]>
+
+* aarch64: correct comment describing BTI
+
+The comment is incorrect, BTI is enabled per mapping via mprotect with
+PROT_BTI flag set, not per-process. When the loader loads the library,
+if the GNU Notes section is missing this, PROT_BTI will not be enabled
+for that mapping, but is independent of other mappings.
+
+Signed-off-by: Bill Roberts <[email protected]>
+
+---------
+
+Signed-off-by: Bill Roberts <[email protected]>
+---
+ src/aarch64/sysv.S    | 4 +++-
+ testsuite/Makefile.am | 2 +-
+ 2 files changed, 4 insertions(+), 2 deletions(-)
+
+diff --git a/src/aarch64/sysv.S b/src/aarch64/sysv.S
+index fdd0e8b7..60cfa505 100644
+--- a/src/aarch64/sysv.S
++++ b/src/aarch64/sysv.S
+@@ -68,7 +68,7 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
+ #define BTI_J hint #36
+ /*
+  * The ELF Notes section needs to indicate if BTI is supported, as the first ELF loaded that doesn't
+- * declare this support disables it for the whole process.
++ * declare this support disables it for memory region containing the loaded library.
+  */
+ # define GNU_PROPERTY_AARCH64_BTI (1 << 0)         /* Has Branch Target Identification */
+ 	.text
+@@ -527,6 +527,7 @@ L(do_closure):
+ #if defined(FFI_EXEC_STATIC_TRAMP)
+ 	.align 4
+ CNAME(ffi_closure_SYSV_V_alt):
++	BTI_C
+ 	/* See the comments above trampoline_code_table. */
+ 	ldr	x17, [sp, #8]			/* Load closure in x17 */
+ 	add	sp, sp, #16			/* Restore the stack */
+@@ -541,6 +542,7 @@ CNAME(ffi_closure_SYSV_V_alt):
+
+ 	.align 4
+ CNAME(ffi_closure_SYSV_alt):
++	BTI_C
+ 	/* See the comments above trampoline_code_table. */
+ 	ldr	x17, [sp, #8]			/* Load closure in x17 */
+ 	add	sp, sp, #16			/* Restore the stack */
+diff --git a/testsuite/Makefile.am b/testsuite/Makefile.am
+index d286cf7f..6ba98e12 100644
+--- a/testsuite/Makefile.am
++++ b/testsuite/Makefile.am
+@@ -8,7 +8,7 @@ CLEANFILES = *.exe core* *.log *.sum
+
+ EXTRA_DIST = config/default.exp emscripten/build.sh emscripten/conftest.py \
+ 	emscripten/node-tests.sh emscripten/test.html emscripten/test_libffi.py \
+-  emscripten/build-tests.sh lib/libffi.exp lib/target-libpath.exp \
++	emscripten/build-tests.sh lib/libffi.exp lib/target-libpath.exp \
+ 	lib/wrapper.exp libffi.bhaible/Makefile libffi.bhaible/README \
+ 	libffi.bhaible/alignof.h libffi.bhaible/bhaible.exp libffi.bhaible/test-call.c \
+ 	libffi.bhaible/test-callback.c libffi.bhaible/testcases.c libffi.call/align_mixed.c \
+

dev-libs/libffi/files/libffi-3.4.6-arm64-fix-build.patch

@@ -0,0 +1,36 @@
+https://github.com/libffi/libffi/commit/9c9e8368e49804c4f7c35ac9f0d7c1d0d533308b
+
+From 9c9e8368e49804c4f7c35ac9f0d7c1d0d533308b Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Martin=20Storsj=C3=B6?= <[email protected]>
+Date: Tue, 4 Jun 2024 14:13:08 +0300
+Subject: [PATCH] aarch64: Add a missing no-op define of SIGN_LR_LINUX_ONLY
+ (#838)
+
+This is needed at least if building for Linux, with a toolchain
+that doesn't default to having PAC enabled, fixing build errors
+since 45d284f2d066cc3a080c5be88e51b4d934349797.
+---
+ src/aarch64/internal.h | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/src/aarch64/internal.h b/src/aarch64/internal.h
+index c39f9cb2..50fa5c13 100644
+--- a/src/aarch64/internal.h
++++ b/src/aarch64/internal.h
+@@ -88,6 +88,7 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
+   #define AUTH_LR_AND_RET retab
+   #define AUTH_LR_WITH_REG(x) autib lr, x
+   #define BRANCH_AND_LINK_TO_REG blraaz
++  #define SIGN_LR_LINUX_ONLY
+   #define BRANCH_TO_REG braaz
+   #define PAC_CFI_WINDOW_SAVE
+   /* Linux PAC Support */
+@@ -136,6 +137,7 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
+     #define AUTH_LR_AND_RET ret
+     #define AUTH_LR_WITH_REG(x)
+     #define BRANCH_AND_LINK_TO_REG blr
++    #define SIGN_LR_LINUX_ONLY
+     #define BRANCH_TO_REG br
+     #define PAC_CFI_WINDOW_SAVE
+   #endif /* HAVE_ARM64E_PTRAUTH */
+