This test case triggers the assert:

pragma(msg, TraceBuf.alignof); // prints 1
struct TraceBuf {
    align(1) uint args;
}

void foo() {
    byte[2] fixDescs;
    TraceBuf fixLog;

    auto dlg = delegate() {
        fixDescs[0] = 1;
        fixLog.args = 1;
    };
}

This is a minimized testcase, that no longer crashes LDC. The original case ran into the error
Error: variable ... overlaps previous field. This is an ICE, please file an LDC issue.

The reason is that the LLVM type is wrong since 1.31.0.

Used to be:
%example.TraceBuf = type <{ i32 }>
but now is:
%example.TraceBuf = type { i32 }, i.e. alignment is not 1 but 4.