Add better support for line breaking across inline box boundaries (#30628)

Earlier versions of inline layout in the new layout system did not
properly support line breaking when unbreakable segments spanned
multiple inline boxes. This change updates inline layout to add support
for that. Now items are added to an unbreakable segment before being
committed to a line.

Co-authored-by: Mukilan Thiyagarajan <mukilan@igalia.com>
Co-authored-by: Oriol Brufau <obrufau@igalia.com>

tests/wpt/meta/css/CSS2/css1/c5502-imrgn-r-000.xht.ini

@@ -1,2 +0,0 @@
-[c5502-imrgn-r-000.xht]
-  expected: FAIL

tests/wpt/meta/css/CSS2/css1/c5502-imrgn-r-002.xht.ini

@@ -1,2 +0,0 @@
-[c5502-imrgn-r-002.xht]
-  expected: FAIL

tests/wpt/meta/css/CSS2/css1/c5504-imrgn-l-000.xht.ini

@@ -1,2 +0,0 @@
-[c5504-imrgn-l-000.xht]
-  expected: FAIL

tests/wpt/meta/css/CSS2/css1/c5504-imrgn-l-002.xht.ini

@@ -1,2 +0,0 @@
-[c5504-imrgn-l-002.xht]
-  expected: FAIL

tests/wpt/meta/css/CSS2/css1/c5507-ipadn-r-000.xht.ini

@@ -1,2 +0,0 @@
-[c5507-ipadn-r-000.xht]
-  expected: FAIL

tests/wpt/meta/css/CSS2/css1/c5507-ipadn-r-002.xht.ini

@@ -1,2 +0,0 @@
-[c5507-ipadn-r-002.xht]
-  expected: FAIL

tests/wpt/meta/css/CSS2/css1/c5509-ipadn-l-000.xht.ini

@@ -1,2 +0,0 @@
-[c5509-ipadn-l-000.xht]
-  expected: FAIL

tests/wpt/meta/css/CSS2/css1/c5509-ipadn-l-002.xht.ini

@@ -1,2 +0,0 @@
-[c5509-ipadn-l-002.xht]
-  expected: FAIL

tests/wpt/meta/css/CSS2/floats/float-nowrap-7.html.ini

@@ -1,2 +0,0 @@
-[float-nowrap-7.html]
-  expected: FAIL

tests/wpt/meta/css/CSS2/floats/float-nowrap-8.html.ini

@@ -1,2 +0,0 @@
-[float-nowrap-8.html]
-  expected: FAIL

tests/wpt/meta/css/CSS2/floats/float-nowrap-9.html.ini

@@ -1,2 +0,0 @@
-[float-nowrap-9.html]
-  expected: FAIL

tests/wpt/meta/css/CSS2/floats/floats-line-wrap-shifted-001.html.ini

@@ -1,2 +0,0 @@
-[floats-line-wrap-shifted-001.html]
-  expected: FAIL