Import portable_atomic::AtomicU64 when std does not provide it

Restores support for 32-bit powerpc and mips. Fixes #10415.

Signed-off-by: Hoang Duc Hieu <code@hdhoang.space>

Cargo.lock

@@ -93,6 +93,7 @@ dependencies = [
  "num-traits",
  "once_cell",
  "pcre2",
+ "portable-atomic",
  "rand",
  "rand_pcg",
  "rsconf",
@@ -319,6 +320,12 @@ version = "0.3.30"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d231b230927b5e4ad203db57bbcbee2802f6bce620b1e4a9024a07d94e2907ec"
 
+[[package]]
+name = "portable-atomic"
+version = "1.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "da544ee218f0d287a911e9c99a39a8c9bc8fcad3cb8db5959940044ecfc67265"
+
 [[package]]
 name = "ppv-lite86"
 version = "0.2.17"