[DataLayout] Remove i1 alignment entry (#156657)

I don't think we need to explicitly specify i1 alignment, as this is
going to fall back to i8 alignment.

This may change behavior if a data layout explicitly sets i8 alignment
without also setting i1 layout, but I'd expect this to be a bug fix in
that case.

Author: nikic

llvm/docs/LangRef.rst

@@ -3273,7 +3273,6 @@ specifications are given in this list:
 -  ``p[n]:64:64:64`` - Other address spaces are assumed to be the
    same as the default address space.
 -  ``S0`` - natural stack alignment is unspecified
--  ``i1:8:8`` - i1 is 8-bit (byte) aligned
 -  ``i8:8:8`` - i8 is 8-bit (byte) aligned as mandated
 -  ``i16:16:16`` - i16 is 16-bit aligned
 -  ``i32:32:32`` - i32 is 32-bit aligned

llvm/lib/IR/DataLayout.cpp

@@ -187,7 +187,6 @@ const char *DataLayout::getManglingComponent(const Triple &T) {
 // Default primitive type specifications.
 // NOTE: These arrays must be sorted by type bit width.
 constexpr DataLayout::PrimitiveSpec DefaultIntSpecs[] = {
-    {1, Align::Constant<1>(), Align::Constant<1>()},  // i1:8:8
     {8, Align::Constant<1>(), Align::Constant<1>()},  // i8:8:8
     {16, Align::Constant<2>(), Align::Constant<2>()}, // i16:16:16
     {32, Align::Constant<4>(), Align::Constant<4>()}, // i32:32:32