Fix build error due to chkstk/alloca on x86
The `avb_cert_validate_vbmeta_public_key` API uses more than 8KB of
stack memory and triggers the compiler to insert calls to function
__chkstk() and __alloca() on x86/x86_64 platforms. Although rust
libcompiler_builtins does provide the implementations, there are
two issues:
1. LLVM mangles the symbol and add an additional underscore to the
symbol name, causing link to fail to find the correct one.
2. The implementation is not enabled for x86 uefi build. x86_64 had the
same issue but was fixed. But it wasn't ported to x86.
As a workaround, for #1 we define mangled symbols that simply jump to
the correct one. For #2 we apply the same fix from x86_64 for x86 at
build time to and rebuild std from source, until upstream is fixed.
Bug: 337114254
Change-Id: Id7bce71a7d5ca08fc79180733e40fc1ec083da57
9 files changed
