3.8 Merge Request: r265134, r263428, r262230, r268386, r268053, r259039

[Daniel Sanders via llvm-commits]

Hi Tom,

Is it ok if I merge these six?
r265134 [MIPS][LLVM-MC] Fix JR encoding for MIPSR6 ISA
r263428 [mips] Fix an issue with long double when function roundl is defined
r262230 [mips] Do not use SLL for ANY_EXTEND nodes as the high bits are undefined.
r268386 [mips][fastisel] ADJCALLSTACKUP has a second immediate operand.
r268053 [mips][FastISel] A store is not a load.
r259039 [mips][microMIPS] Disable FastISel for microMIPS