syntax_data: {"ast_node_type":"other","tokens":[{"end":70,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:         // be supported via options similar to AArch64's -Z fixed-x18.
context_before:         // There are currently no builtin targets that use them, but in the future they may need to
context_after:         r2: reg = ["r2", "g2"], // % reserved_g2