Auto merge of #46573 - jseyfried:add_decl_macro_test, r=nrc
Auto merge of #46573 - jseyfried:add_decl_macro_test, r=nrc

macros: add test for #44128

Closes #44128.
r? @nrc

aidancully/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,graydon/rust,aidancully/rust,GBGamer/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,GBGamer/rust,graydon/rust,aidancully/rust,GBGamer/rust,GBGamer/rust