[llvm] [BOLT] Ignore duplicate global symbols (PR #201082)

[Jinjie Huang via llvm-commits]

Jinjie-Huang wrote:

@yavtuk Hi! Thanks for stepping in. Overall, the proportion of these duplicate symbols is relatively low. In a case, out of the 43 dynamic libraries used by our internal main binary, only 2 exhibit this issue of duplicated global symbols in '.symtab'. This makes sense because it primarily affects symbols exported as public APIs. 

Here are some statistics, proportion within the individual shared libraries:
1. libbsd.so: 3.06% (3 / 98) duplicate symbols
2. libnuma.so: 16.67% (14 / 84) duplicate symbols

When linked into the main binary as static archives: 0.01% (15 / 104710) duplicate symbols

https://github.com/llvm/llvm-project/pull/201082