Revert r367501 "Create unique, but identically-named ELF sections..."

This reverts commit fbc563e2cb6c5f1d0200b390513506b6aca4d2e9 "Create
unique, but identically-named ELF sections for explicitly-sectioned
functions and globals when using -function-sections and
-data-sections."

Reason for revert: sections are created with potentially wrong
attributes.

llvm-svn: 368204