[BOLT][TEST] Import small tests

Summary:
Imported small internal tests:
- fallthrough-to-noop.test

(cherry picked from FBD32158100)

bolt/test/X86/Inputs/ft_to_noop.s

@@ -0,0 +1,60 @@
+.file	"ft_to_noop.s"
+.text
+
+.globl	foo
+.type	foo, @function
+foo:
+LFB0:
+# FDATA: 0 [unknown] 0 1 foo 0 0 20
+	.cfi_startproc
+	pushq	%rbp
+	.cfi_def_cfa_offset 16
+	.cfi_offset 6, -16
+	movq	%rsp, %rbp
+	.cfi_def_cfa_register 6
+	movl	%edi, -20(%rbp)
+	movl	$0, -4(%rbp)
+	cmpl	$10, -20(%rbp)
+LBB00_br:
+	jle	L2
+  nop
+# FDATA: 1 foo #LBB00_br# 1 foo #L2# 0 18
+# FDATA: 1 foo #LBB00_br# 1 foo #LFT0# 0 3
+
+LFT0:
+	movl	-20(%rbp), %eax
+	addl	$1, %eax
+	movl	%eax, -4(%rbp)
+L2:
+	addl	$1, -4(%rbp)
+	movl	-4(%rbp), %eax
+	popq	%rbp
+	.cfi_def_cfa 7, 8
+	ret
+	.cfi_endproc
+LFE0:
+	.size	foo, .-foo
+
+.globl	main
+.type	main, @function
+main:
+LFB1:
+	.cfi_startproc
+	pushq	%rbp
+	.cfi_def_cfa_offset 16
+	.cfi_offset 6, -16
+	movq	%rsp, %rbp
+	.cfi_def_cfa_register 6
+	subq	$16, %rsp
+	movl	%edi, -4(%rbp)
+	movq	%rsi, -16(%rbp)
+	movl	-4(%rbp), %eax
+	movl	%eax, %edi
+	call	foo
+	movl	$0, %eax
+	leave
+	.cfi_def_cfa 7, 8
+	ret
+	.cfi_endproc
+LFE1:
+	.size	main, .-main

bolt/test/X86/fallthrough-to-noop.test

@@ -0,0 +1,30 @@
+# Check that profile data for the fall-through jump is not ingored when there is
+# a conditional jump followed by a no-op.
+
+RUN: llvm-mc -filetype=obj -triple x86_64-unknown-unknown \
+RUN:   %S/Inputs/ft_to_noop.s -o %t.o
+RUN: link_fdata %S/Inputs/ft_to_noop.s %t.o %t.fdata
+RUN: llvm-strip --strip-unneeded %t.o
+RUN: %clang %t.o -o %t.exe -Wl,-q
+RUN: llvm-bolt %t.exe -o %t -data %t.fdata \
+RUN:   -print-cfg -sequential-disassembly 2>&1 | FileCheck %s
+
+CHECK:      Binary Function "foo" after building cfg
+CHECK:        Exec Count  : 20
+CHECK:        Profile Acc : 100.0%
+
+# This block is terminated with a conditional jump to .Ltmp0 followed by a
+# no-op. The profile data contains a count for the fall-through (3) which
+# is different from what would be inferred (2). However the destination
+# offset of this fall-through jump in the profile data points to the no-op
+# following the jump and not the start of the fall-through block .LFT0.
+CHECK:      Entry Point
+CHECK-NEXT:   Exec Count : 20
+CHECK:        Successors: .Ltmp[[#BB1:]] (mispreds: 0, count: 18), .LFT[[#BB2:]] (mispreds: 0, count: 3)
+
+CHECK:      .LFT[[#BB2]]
+CHECK-NEXT:   Exec Count : 3
+CHECK:        Successors: .Ltmp[[#]] (mispreds: 0, count: 0)
+
+CHECK:      .Ltmp[[#BB1]]
+CHECK-NEXT:   Exec Count : 18