basop-2308-optimisation-of-find-target [non-be][rend-non-be][split-non-be][allow-regression]

• Related issues: #2308 (closed)
• Requested reviewers: @jander , results are as expected, if you have a few minutes to have a look into the modifications, just to be sure I didn't miss something, would be appreciated

Reason why this change is needed

the computation of the impulse response inside find_target is unnecessary complex.

|------------|---before--|---after---| | WMOPS Max. | 3.8 wmops | 3.4 wmops |

Description of the change

replace W_msu_16_16(a, b, extract_h(L_shl(c,x)) by Using W_msu_32_16(a, L_shl(c,x), b)

Affected operating points

• All operating point that are using acelp core
• 2. Produced bitstream is non-BE but it is fully backwards compatible for decoding. Decoded output may differ.