[ports/*] Fix cross-compilation issues (#4493)

OpenSSL needs a patch to properly cross compile under rv64; fix infinite recursion with A32 thunks.
Updated cross build guide as well.

Signed-off-by: lizzie <lizzie@eden-emu.dev>

- [x] I have read and followed the [Contribution Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/CONTRIBUTING.md#code-contributions).
- [x] I have read and followed the [AI Policy](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/AI.md)
- [x] I have read and followed the [Coding Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/Coding.md) to the best of my ability.

-------------------

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4493
Reviewed-by: crueter <crueter@eden-emu.dev>

externals/cmake-modules/DetectArchitecture.cmake

@@ -101,6 +101,11 @@ endfunction()
 # ia64 exists
 # the rest exist, but are probably less popular than ia64
 
+detect_architecture_symbols(
+    ARCH wasm
+    SYMBOLS
+        "__EMSCRIPTEN__")
+
 detect_architecture_symbols(
     ARCH arm64
     SYMBOLS
@@ -203,11 +208,6 @@ detect_architecture_symbols(
         "__loongarch__"
         "__loongarch64")
 
-detect_architecture_symbols(
-    ARCH wasm
-    SYMBOLS
-        "__EMSCRIPTEN__")
-
 # "generic" target
 # If you have reached this point, you're on some as-of-yet unsupported architecture.
 # See the docs up above for known unsupported architectures