Alpine Linux is distinct from Ubuntu/Debian because Alpine's standard library uses musl instead of glibc. Alpine Linux is guaranteed to build, but there is no constant-time tests on Alpine. (#2308) [skip ci]

Signed-off-by: Ganyu (Bruce) Xu <[email protected]>

Author: xuganyu96

PLATFORMS.md

@@ -58,6 +58,7 @@ In this policy, the words "must" and "must not" specify absolute requirements th
 - aarch64 for Apple iOS and tvOS (CMake `-DPLATFORM=OS64` and `TVOS`)
 - arm64, arm (32 bit), x86, x86_64, riscv32, riscv64 for Zephyr
 - armhf/ARM7 emulation on Ubuntu
+- amd64 for Alpine Linux
 
 ### Tier 3