[RISCV][NFC] Expand test/MC/RISCV/linker-relaxation.s tests
[RISCV][NFC] Expand test/MC/RISCV/linker-relaxation.s tests

Add more complete CHECK lines for the relocations generated when relaxation is
enabled, and add cases where a locally defined symbol is referenced.

Two instances of pcrel_lo(defined_symbol) are commented out, as they will
produce an error. A follow-up patch will fix this.



git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@356734 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/llvm,apple/swift-llvm,apple/swift-llvm,llvm-mirror/llvm,apple/swift-llvm,llvm-mirror/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm