New WASI SDK package should contain a new version of the linker. Also, the script should now create an installable package on macOS so that one could create a full SwiftWasm package later after the build.

* Update WASI SDK, create installable package on macOS

* Fix sysroot path, update wasi-sdk on Linux

* Exclude module net for wasm SDK in glibc.modulemap

* Remove module termios from glic.modulemap for wasm

* Disable _stdlib_mkstemps for wasm

Apply the same control-flow changes to the method that were applied on
main to avoid duplicated implementations one of which crashes with

```
Metadata for archetype not bound in function.
  The metadata could be missing entirely because it needs to be passed to the function.
  Or the metadata is present and not bound in which case setScopedLocalTypeMetadata or similar must be called.
Archetype without metadata: Value
(primary_archetype_type address=0x14207ebe0 conforms_to="Swift.(file).Escapable" name="Value"
  (interface_type=generic_type_param_type depth=0 index=0 decl="Synchronization.(file)._Cell.Value@/path/to/swift/6_0_0_6/swift/stdlib/public/Synchronization/Cell.swift:19:23"))
Function:
; Function Attrs: noinline nounwind
define linkonce_odr hidden ptr @"$s15Synchronization5_CellVyxGRi_zlWOb"(ptr %0, ptr %1, ptr %2) #14 !dbg !8 {
  %4 = alloca i1, align 1
}
LocalTypeData:
(0x14207f5f8 (_Cell<Value>), FormalTypeMetadata) => [
  (universal) concrete: 0x600003d1add0
    ptr %2
]
```

when building Synchronization.