[compiler-rt/profile] Hide __llvm_profile_raw_version
Hide __llvm_profile_raw_version so as not to resolve reference from a dependent shared object. Since libclang_rt.profile is added later in the command line, a definition of __llvm_profile_raw_version is not included if it is provided from an earlier object, e.g. from a shared dependency. This causes an extra dependence edge where if libA.so depends on libB.so and both are coverage-instrumented, libA.so uses libB.so's definition of __llvm_profile_raw_version. This leads to a runtime link failure if the libB.so available at runtime does not provide this symbol (but provides the other dependent symbols). Such a scenario can occur in Android's mainline modules. E.g.: ld -o libB.so libclang_rt.profile-x86_64.a ld -o libA.so -l B libclang_rt.profile-x86_64.a libB.so has a global definition of __llvm_profile_raw_version. libA.so uses libB.so's definition of __llvm_profile_raw_version. At runtime, libB.so may not be coverage-instrumented (i.e. not export __llvm_profile_raw_version) so runtime linking of libA.so will fail. Marking this symbol as hidden forces each binary to use the definition of __llvm_profile_raw_version from libclang_rt.profile. Differential Revision: https://reviews.llvm.org/D111759
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