[llvm] [BOLT][AArch64] Add base_cflags for PI flags (PR #145502)

[Paschalis Mpeis via llvm-commits]

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@@ -1,7 +1,10 @@
 if "AArch64" not in config.root.targets:
     config.unsupported = True
 
-flags = "--target=aarch64-unknown-linux-gnu -nostartfiles -nostdlib -ffreestanding"
+flags = "-nostartfiles -nostdlib -ffreestanding"
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paschalis-mpeis wrote:

Could send a separate patch for this. The [host_triple](https://github.com/llvm/llvm-project/pull/145502/files#diff-a2f6c99c681f9d341dea2ed9c075c14d88e40235f2a31ed8f5ee7690cf63ce5aR5) in the parent lit.local.cfg should already cover it.

https://github.com/llvm/llvm-project/pull/145502