BaseTools/GenFw: Parse IBT/BTI support status from ELF note

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4405

When performing ELF to PE/COFF conversion, parse any notes sections to
decide whether the image supports forward CFI landing pads. This will be
used to set the associated DllCharacteristicsEx flag in a subsequent
patch.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Leif Lindholm <quic_llindhol@quicinc.com>
Reviewed-by: Oliver Smith-Denny <osde@linux.microsoft.com>
Acked-by: Michael Kubacki <michael.kubacki@microsoft.com>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>

BaseTools/Source/C/GenFw/elf_common.h

@@ -59,6 +59,15 @@ typedef struct {
   UINT32  n_type;    /* Type of this note. */
 } Elf_Note;
 
+#define NT_GNU_PROPERTY_TYPE_0  5
+
+#define GNU_PROPERTY_X86_FEATURE_1_AND  0xc0000002
+#define GNU_PROPERTY_X86_FEATURE_1_IBT  0x1
+
+#define GNU_PROPERTY_AARCH64_FEATURE_1_AND  0xc0000000
+#define GNU_PROPERTY_AARCH64_FEATURE_1_BTI  0x1
+#define GNU_PROPERTY_AARCH64_FEATURE_1_PAC  0x2
+
 /* Indexes into the e_ident array.  Keep synced with
    http://www.sco.com/developers/gabi/latest/ch4.eheader.html */
 #define EI_MAG0    0  /* Magic number, byte 0. */