Fix method handles using wrong section

For compact dex, the method handles were using offsets relative to
data section instead of main section. Fixed this code and the map
list offset logic in InitializeSectionsFromMapList.

Test: test/run-test  --always-clean --dex2oat-jobs 4 --host --prebuild --compact-dex-level fast --optimizing --no-relocate --runtime-option -Xcheck:jni 979-const-method-handle
Bug: 63756964
Change-Id: I9e6ddfd77da99ae1aedef7591536be190ff60904