Do not set the rounding mode before exact floating-point operations.

Setting the rounding mode on some host architectures (including x86, according to <http://www.mega-nerd.com/FPcast/>) empties the floating-point unit's pipeline, resulting in poorer performance. Omitting the rounding mode before exact operations restores some performance.

Affected opcodes are CVT.W.S, CVT.W.D, CVT.L.S, CVT.L.D, ABS.S, MOV.S, NEG.S, ABS.D, MOV.D and NEG.D.
Do not set the rounding mode before floating-point widening conversions.

The rounding mode is completely unneeded when converting from W (32-bit integer) or S (32-bit floating-point) to D (64-bit floating-point), and is actually unused on MIPS processors.

Quoting from the MIPS Programmer's Manual, volume 2, for CVT.D.fmt:
The value in FPR fs, in format fmt, is converted to a value in double floating point format and rounded according to the current rounding mode in FCSR. The result is placed in FPR fd. If fmt is S or W, then the operation is always exact.
Remove a native test and branch from inter-block jumps.
Allow to load CountPerOp info from mupen64plus.ini

The CountPerOp settings has to be adjusted for each ROM. It is easier for the
enduser when the default value is not hardcoded in mupen64plus and instead
this dynamic information is retreived from the mupen64plus.ini.
Add CountPerOp info to mupen64plus.ini

The CountPerOp settings has to be adjusted for each ROM. It is easier for the
enduser when the default value is not hardcoded in mupen64plus and instead
this dynamic information is retreived from the mupen64plus.ini.
Avoid level restart through lianes swinging in Donkey Kong 64 (U/J)
Merge pull request #4 from Nebuleon/master

Optimisations.
Merge pull request #5 from ecsv/countperop_db

Load CountPerOp info from mupen64plus.ini
Merge pull request #6 from littleguy77/master

Fix some RefMD5 values in mupen64plus.ini