[llvm] [AArch64][SME] Use reportFatalUsageError rather than assert (NFC) (PR #145491)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,7 @@
+; RUN: not llc -mtriple aarch64-none-linux-gnu %s 2>&1 | FileCheck %s
+
+; CHECK: LLVM ERROR: streaming SVE functions require SME
+define void @streaming(i64 noundef %n) "aarch64_pstate_sm_enabled" nounwind {
+entry:
+  ret void
+}
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arsenm wrote:

could also probably turn this into a proper LLVMContext error 

https://github.com/llvm/llvm-project/pull/145491