[Tools] Accelerate model loading.

[marvin-Yu]

qwen 7b loading time from 24s to 16s;
qwen 72b loading time from 517s to 400s;

[pujiang2018]

1. need to be careful to add omp in float16.h, as the outer scope may already assume it is in simple thread, and contains omp at the outside scope.
2. can we remove filesystem linkage? (as current binary is already big, we may only add new library when it is a MUST)

[Duyi-Wang]

1. need to be careful to add omp in float16.h, as the outer scope may already assume it is in simple thread, and contains omp at the outside scope.
2. can we remove filesystem linkage? (as current binary is already big, we may only add new library when it is a MUST)

We have introduced filesystem in debugger.h

[pujiang2018]

1. need to be careful to add omp in float16.h, as the outer scope may already assume it is in simple thread, and contains omp at the outside scope.
2. can we remove filesystem linkage? (as current binary is already big, we may only add new library when it is a MUST)

We have introduced filesystem in debugger.h

there is a difference that debugger will ONLY be effective when DEBUG is enabled.