[llvm] [XCOFF] make related SD symbols as isFunction (PR #69553)

[via llvm-commits]

diggerlin wrote:

in the function  XCOFFSymbolRef::isFunction(), there is 

https://github.com/llvm/llvm-project/blob/main/llvm/lib/Object/XCOFFObjectFile.cpp#L1251C1-L1263C70

if there a possible that  a function definition symbol  has the Symbol storage mapping is XMC_PR , but not put in the .text section.
@stephenpeckham , @chenzheng1030.

https://github.com/llvm/llvm-project/pull/69553