Found during crossgening powershell with Checked JIT (with mibc data).
BBF_HAS_IDX_LEN is not set on BB06 but is required because of the following tree
N006 ( 3, 3) [000123] ---X-------- * ARR_LENGTH int
N005 ( 1, 1) [000122] ------------ \--* LCL_VAR ref V01 loc0 u:1
C:\prj\runtime\src\coreclr\jit\earlyprop.cpp:115
Assertion failed 'false' in 'System.Net.Security.TlsFrameHelper:DecodeString(System.ReadOnlySpan`1[System.Byte]):System.String'
during 'Early Value Propagation' (IL size 41)
Found during crossgening powershell with Checked JIT (with mibc data).