[tests] Add Malayalam tests frim cibu
[Indic] Sort pre-base reordering consonants with post-forms

Before, we were marking them as below-form for initial reordering.
However, there is a rule that says "post consonants should follow
below consonsnts" for base determination purposes.  Malayalam has
port-form YA/VA, and RA is pre-base.  As such, for a sequence like
YA,Virama,YA,Virama,RA, the correct base is at index 0.  But
because the code was seeing RA as a below-base, it was stopping at
the second YA as base, instead of jumping it as a post-base.

By treating prebase-reordering consonants like post-forms, this
is fixed.

MALAYALAM went down from 351 to 265.  Other numbers didn't change:

BENGALI: 353686 out of 354188 tests passed. 502 failed (0.141733%)
DEVANAGARI: 707305 out of 707394 tests passed. 89 failed (0.0125814%)
GUJARATI: 366262 out of 366457 tests passed. 195 failed (0.0532122%)
GURMUKHI: 60706 out of 60747 tests passed. 41 failed (0.067493%)
KANNADA: 950680 out of 951913 tests passed. 1233 failed (0.129529%)
KHMER: 299074 out of 299124 tests passed. 50 failed (0.0167155%)
LAO: 53611 out of 53644 tests passed. 33 failed (0.0615167%)
MALAYALAM: 1048069 out of 1048334 tests passed. 265 failed (0.0252782%)
ORIYA: 42320 out of 42329 tests passed. 9 failed (0.021262%)
SINHALA: 271539 out of 271847 tests passed. 308 failed (0.113299%)
TAMIL: 1091753 out of 1091754 tests passed. 1 failed (9.15957e-05%)
TELUGU: 970555 out of 970573 tests passed. 18 failed (0.00185457%)
TIBETAN: 208469 out of 208469 tests passed. 0 failed (0%)