[llvm] [AArch64][GlobalISel] Basic SVE and fadd (PR #72976)

[Matt Arsenault via llvm-commits]

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@@ -51,6 +51,8 @@
 
 using namespace llvm;
 
+extern cl::opt<bool> DisableSVEGISel;
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arsenm wrote:

Seems unnecessary. I don't think this should be a long lived option 

https://github.com/llvm/llvm-project/pull/72976