This patch addresses compatibility issues with the lit internal shell by
removing the use of subshell execution (parentheses and subshell syntax)
in the `BOLT` tests. The lit internal shell does not support
parentheses, so the tests have been refactored to use separate command
invocations, with outputs redirected to temporary files where necessary.
This change is relevant for enabling the lit internal shell by default,
as outlined in [[RFC] Enabling the Lit Internal Shell by
Default](https://discourse.llvm.org/t/rfc-enabling-the-lit-internal-shell-by-default/80179)
fixes: #102401
7f3793207b