[Bug target/113971] [14 Regression] failure to build on arm64 musl (#error "Unsupported AArch64 platform for heap trampolines")

[iains at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113971

--- Comment #1 from Iain Sandoe <iains at gcc dot gnu.org> ---
the intent was not to enable this feature for platforms we could not test.
but libgcc/config.host has "aarch64*-*-linux*" so we have inadvertently enabled
it for aarch64-linux-musl.


assuming linux-musl defines __linux__ ... something like:

diff --git a/libgcc/config/aarch64/heap-trampoline.c
b/libgcc/config/aarch64/heap-trampoline.c
index 9d5b19983b1..1e3460b1601 100644
--- a/libgcc/config/aarch64/heap-trampoline.c
+++ b/libgcc/config/aarch64/heap-trampoline.c
@@ -29,7 +29,7 @@ void *allocate_trampoline_page (void);
 void __gcc_nested_func_ptr_created (void *chain, void *func, void *dst);
 void __gcc_nested_func_ptr_deleted (void);

-#if defined(__gnu_linux__)
+#if defined(__linux__)
 static const uint32_t aarch64_trampoline_insns[] = {
   0xd503245f, /* hint    34 */
   0x580000b1, /* ldr     x17, .+20 */
@@ -82,7 +82,7 @@ allocate_trampoline_page (void)
 {
   void *page;

-#if defined(__gnu_linux__)
+#if defined(__linux__)
   page = mmap (0, getpagesize (), PROT_WRITE | PROT_EXEC,
               MAP_ANON | MAP_PRIVATE, 0, 0);
 #elif __APPLE__